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Tetrahedron

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830: 14037: 12743: 2872: 2953: 14452: 14423: 12969: 12962: 12976: 12955: 5115: 13943: 198: 13957: 2572: 12778: 12764: 14141: 8480: 10056: 13783: 12771: 3121: 12573: 12559: 5587: 12750: 4880: 12948: 12566: 5581: 181: 13111: 12545: 12757: 12989: 13610: 12538: 5264: 13104: 12921: 12552: 5404: 3051: 12339: 1647: 3161: 3042: 13097: 13083: 13069: 13811: 13790: 13603: 13090: 13076: 13062: 12914: 12928: 14432: 12907: 6720: 2946: 5314: 13804: 13797: 13596: 13589: 13582: 12900: 12788: 12712: 5505: 5013: 3186: 13818: 12719: 9673: 13575: 13436: 12526: 5511: 13929: 7802: 12512: 169: 14673: 13443: 13422: 13408: 12491: 2979: 2840: 14129: 12698: 13839: 13631: 12519: 12691: 13860: 13853: 13846: 13652: 13645: 13638: 1186: 5188: 12705: 2228: 13624: 13617: 14514: 2847: 13450: 12505: 328: 11923: 13832: 13825: 13429: 13401: 12498: 13415: 14347: 12726: 6539: 825: 10051:{\displaystyle {\begin{vmatrix}-1&\cos {(\alpha _{12})}&\cos {(\alpha _{13})}&\cos {(\alpha _{14})}\\\cos {(\alpha _{12})}&-1&\cos {(\alpha _{23})}&\cos {(\alpha _{24})}\\\cos {(\alpha _{13})}&\cos {(\alpha _{23})}&-1&\cos {(\alpha _{34})}\\\cos {(\alpha _{14})}&\cos {(\alpha _{24})}&\cos {(\alpha _{34})}&-1\\\end{vmatrix}}=0\,} 1114: 14443: 7480: 2007: 9587:: the point where the six midplanes of a tetrahedron intersect. A midplane is defined as a plane that is orthogonal to an edge joining any two vertices that also contains the centroid of an opposite edge formed by joining the other two vertices. If the tetrahedron's altitudes do intersect, then the Monge point and the orthocenter coincide to give the class of 7465: 6067: 12334:{\displaystyle {\begin{aligned}C&=A^{-1}B&{\text{where}}&\ &A=\left({\begin{matrix}\left^{T}\\\left^{T}\\\left^{T}\end{matrix}}\right)&\ &{\text{and}}&\ &B={\frac {1}{2}}\left({\begin{matrix}\|x_{1}\|^{2}-\|x_{0}\|^{2}\\\|x_{2}\|^{2}-\|x_{0}\|^{2}\\\|x_{3}\|^{2}-\|x_{0}\|^{2}\end{matrix}}\right)\\\end{aligned}}} 10897: 1642:{\displaystyle {\begin{aligned}{\frac {d_{1}^{4}+d_{2}^{4}+d_{3}^{4}+d_{4}^{4}}{4}}+{\frac {16R^{4}}{9}}&=\left({\frac {d_{1}^{2}+d_{2}^{2}+d_{3}^{2}+d_{4}^{2}}{4}}+{\frac {2R^{2}}{3}}\right)^{2},\\4\left(a^{4}+d_{1}^{4}+d_{2}^{4}+d_{3}^{4}+d_{4}^{4}\right)&=\left(a^{2}+d_{1}^{2}+d_{2}^{2}+d_{3}^{2}+d_{4}^{2}\right)^{2}.\end{aligned}}} 4844:) copies of itself to tile space. The cube can be dissected into six 3-orthoschemes, three left-handed and three right-handed (one of each at each cube face), and cubes can fill space, so the characteristic 3-orthoscheme of the cube is a space-filling tetrahedron in this sense. (The characteristic orthoscheme of the cube is one of the 1846: 2907: 6874: 652: 9358: 6715:{\displaystyle 36\cdot V^{2}={\begin{vmatrix}\mathbf {a^{2}} &\mathbf {a} \cdot \mathbf {b} &\mathbf {a} \cdot \mathbf {c} \\\mathbf {a} \cdot \mathbf {b} &\mathbf {b^{2}} &\mathbf {b} \cdot \mathbf {c} \\\mathbf {a} \cdot \mathbf {c} &\mathbf {b} \cdot \mathbf {c} &\mathbf {c^{2}} \end{vmatrix}}} 950: 14120:, a large frame in the shape of a tetrahedron with two sides covered with a thin material is mounted on a rotating pivot and always points into the wind. It is built big enough to be seen from the air and is sometimes illuminated. Its purpose is to serve as a reference to pilots indicating wind direction. 7797:{\displaystyle 288\cdot V^{2}={\begin{vmatrix}0&1&1&1&1\\1&0&d_{12}^{2}&d_{13}^{2}&d_{14}^{2}\\1&d_{12}^{2}&0&d_{23}^{2}&d_{24}^{2}\\1&d_{13}^{2}&d_{23}^{2}&0&d_{34}^{2}\\1&d_{14}^{2}&d_{24}^{2}&d_{34}^{2}&0\end{vmatrix}}} 3224:
in which all edges are mutually perpendicular. In a 3-dimensional orthoscheme, the tree consists of three perpendicular edges connecting all four vertices in a linear path that makes two right-angled turns. The 3-orthoscheme is a tetrahedron having two right angles at each of two vertices, so another
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yields four such identities, but at most three of them are independent: If the "clockwise" sides of three of them are multiplied and the product is inferred to be equal to the product of the "counterclockwise" sides of the same three identities, and then common factors are cancelled from both sides,
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The above embedding divides the cube into five tetrahedra, one of which is regular. In fact, five is the minimum number of tetrahedra required to compose a cube. To see this, starting from a base tetrahedron with 4 vertices, each added tetrahedra adds at most 1 new vertex, so at least 4 more must be
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The iterative LEB of the regular tetrahedron has been shown to produce only 8 similarity classes. Furthermore, in the case of nearly equilateral tetrahedra where their two longest edges are not connected to each other, and the ratio between their longest and their shortest edge is less than or equal
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Tetrahedra subdivision is a process used in computational geometry and 3D modeling to divide a tetrahedron into several smaller tetrahedra. This process enhances the complexity and detail of tetrahedral meshes, which is particularly beneficial in numerical simulations, finite element analysis, and
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Three angles are the angles of some triangle if and only if their sum is 180° (π radians). What condition on 12 angles is necessary and sufficient for them to be the 12 angles of some tetrahedron? Clearly the sum of the angles of any side of the tetrahedron must be 180°. Since there are four such
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is the set of tetrahedra with the same geometric shape, regardless of their specific position, orientation, and scale. So, any two tetrahedra belonging to the same similarity class may be transformed to each other by an affine transformation. The outcome of having a limited number of similarity
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If one relaxes the requirement that the tetrahedra be all the same shape, one can tile space using only tetrahedra in many different ways. For example, one can divide an octahedron into four identical tetrahedra and combine them again with two regular ones. (As a side-note: these two kinds of
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to a chosen face is coplanar with two other orthogonal lines to the same face. The first is an orthogonal line passing through the corresponding Euler point to the chosen face. The second is an orthogonal line passing through the centroid of the chosen face. This orthogonal line through the
7166: 5807: 10681: 6524: 8475: 7240: 2223:{\displaystyle {\begin{aligned}\left({\sqrt {\frac {8}{9}}},0,-{\frac {1}{3}}\right),&\quad \left(-{\sqrt {\frac {2}{9}}},{\sqrt {\frac {2}{3}}},-{\frac {1}{3}}\right),\\\left(-{\sqrt {\frac {2}{9}}},-{\sqrt {\frac {2}{3}}},-{\frac {1}{3}}\right),&\quad (0,0,1)\end{aligned}}} 10430:
is thereby reduced from 12 to 8. The four relations given by this sine law further reduce the number of degrees of freedom, from 8 down to not 4 but 5, since the fourth constraint is not independent of the first three. Thus the space of all shapes of tetrahedra is 5-dimensional.
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is the height from the base to the apex. This applies for each of the four choices of the base, so the distances from the apices to the opposite faces are inversely proportional to the areas of these faces. Another way is by dissecting a triangular prism into three pieces.
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It has 8 isometries. If edges (1,2) and (3,4) are of different length to the other 4 then the 8 isometries are the identity 1, reflections (12) and (34), and 180° rotations (12)(34), (13)(24), (14)(23) and improper 90° rotations (1234) and (1432) forming the symmetry group
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classes in iterative subdivision methods is significant for computational modeling and simulation. It reduces the variability in the shapes and sizes of generated tetrahedra, preventing the formation of highly irregular elements that could compromise simulation results.
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is a tetrahedron with four congruent triangles as faces; the triangles necessarily have all angles acute. The regular tetrahedron is a special case of a disphenoid. Other names for the same shape include bisphenoid, isosceles tetrahedron and equifacial tetrahedron.
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Coxeter also calls quadrirectangular tetrahedra "characteristic tetrahedra", because of their integral relationship to the regular polytopes and their symmetry groups. For example, the special case of a 3-orthoscheme with equal-length perpendicular edges is
2899:. The aspect ratio of the rectangle reverses as you pass this halfway point. For the midpoint square intersection the resulting boundary line traverses every face of the tetrahedron similarly. If the tetrahedron is bisected on this plane, both halves become 6151: 2428: 9661:
twelve-point center lies midway between the Euler point orthogonal line and the centroidal orthogonal line. Furthermore, for any face, the twelve-point center lies at the midpoint of the corresponding Euler point and the orthocenter for that face.
820:{\displaystyle {\begin{aligned}\arccos \left({\frac {1}{3}}\right)&=\arctan \left(2{\sqrt {2}}\right)\approx 70.529^{\circ },\\\arccos \left(-{\frac {1}{3}}\right)&=2\arctan \left({\sqrt {2}}\right)\approx 109.471^{\circ }.\end{aligned}}} 9645:, one third of the way from the Monge point toward each of the four vertices. Finally it passes through the four base points of orthogonal lines dropped from each Euler point to the face not containing the vertex that generated the Euler point. 11658: 6245: 474: 511: 8886: 7845:
is the pairwise distance between them – i.e., the length of the edge connecting the two vertices. A negative value of the determinant means that a tetrahedron cannot be constructed with the given distances. This formula, sometimes called
6319: 4538:, first from a tetrahedron vertex to an tetrahedron edge center, then turning 90° to an tetrahedron face center, then turning 90° to the tetrahedron center. The orthoscheme has four dissimilar right triangle faces. The exterior face is a 14246:, also has a tetrahedral structure, with two hydrogen atoms and two lone pairs of electrons around the central oxygen atoms. Its tetrahedral symmetry is not perfect, however, because the lone pairs repel more than the single O–H bonds. 8145: 14491:
computer and other aspects of the movie. Kubrick scrapped the idea of using the tetrahedron as a visitor who saw footage of it did not recognize what it was and he did not want anything in the movie regular people did not understand.
1109:{\displaystyle {\begin{aligned}R={\frac {\sqrt {6}}{4}}a,&\qquad r={\frac {1}{3}}R={\frac {a}{\sqrt {24}}},\\r_{\mathrm {M} }={\sqrt {rR}}={\frac {a}{\sqrt {8}}},&\qquad r_{\mathrm {E} }={\frac {a}{\sqrt {6}}}.\end{aligned}}} 10159:. Unlike the case of the other Platonic solids, all the vertices of a regular tetrahedron are equidistant from each other (they are the only possible arrangement of four equidistant points in 3-dimensional space, for an example in 8330: 11874:
The circumcenter of a tetrahedron can be found as intersection of three bisector planes. A bisector plane is defined as the plane centered on, and orthogonal to an edge of the tetrahedron. With this definition, the circumcenter
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to the midpoint of an edge of the base. This follows from the fact that the medians of a triangle intersect at its centroid, and this point divides each of them in two segments, one of which is twice as long as the other (see
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we can recognize an orthoscheme (the characteristic tetrahedron of the cube), a double orthoscheme (the characteristic tetrahedron of the cube face-bonded to its mirror image), and the space-filling disphenoid illustrated
10095:, and at which the angles subtended by opposite edges are equal. A solid angle of π sr is one quarter of that subtended by all of space. When all the solid angles at the vertices of a tetrahedron are smaller than π sr, 8891: 7460:{\displaystyle 6\cdot V=\left|\det \left({\begin{matrix}a_{1}&b_{1}&c_{1}&d_{1}\\a_{2}&b_{2}&c_{2}&d_{2}\\a_{3}&b_{3}&c_{3}&d_{3}\\1&1&1&1\end{matrix}}\right)\right|\,.} 7017: 9563: 6330: 1875: 11535:
This formula is obtained from dividing the tetrahedron into four tetrahedra whose points are the three points of one of the original faces and the incenter. Since the four subtetrahedra fill the volume, we have
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The tetrahedron has many properties analogous to those of a triangle, including an insphere, circumsphere, medial tetrahedron, and exspheres. It has respective centers such as incenter, circumcenter, excenters,
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The tetrahedron with regular faces is a solution to an old puzzle asking to form four equilateral triangles using six unbroken matchsticks. The solution places the matchsticks along the edges of a tetrahedron.
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An orthogonal line dropped from the Monge point to any face meets that face at the midpoint of the line segment between that face's orthocenter and the foot of the altitude dropped from the opposite vertex.
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This gives two opposite edges (1,2) and (3,4) that are perpendicular but different lengths, and then the 4 isometries are 1, reflections (12) and (34) and the 180° rotation (12)(34). The symmetry group is
4934:. The disphenoid is the double orthoscheme face-bonded to its mirror image (a quadruple orthoscheme). Thus all three of these Goursat tetrahedra, and all the polyhedra they generate by reflections, can be 10270: 6062:{\displaystyle {\begin{aligned}\mathbf {a} &=(a_{1},a_{2},a_{3}),\\\mathbf {b} &=(b_{1},b_{2},b_{3}),\\\mathbf {c} &=(c_{1},c_{2},c_{3}),\\\mathbf {d} &=(d_{1},d_{2},d_{3}).\end{aligned}}} 5131:
It gives 6 isometries, corresponding to the 6 isometries of the base. As permutations of the vertices, these 6 isometries are the identity 1, (123), (132), (12), (13) and (23), forming the symmetry group
7009: 6965: 6921: 10892:{\displaystyle \Delta _{i}^{2}=\Delta _{j}^{2}+\Delta _{k}^{2}+\Delta _{l}^{2}-2(\Delta _{j}\Delta _{k}\cos \theta _{il}+\Delta _{j}\Delta _{l}\cos \theta _{ik}+\Delta _{k}\Delta _{l}\cos \theta _{ij})} 12344:
In contrast to the centroid, the circumcenter may not always lay on the inside of a tetrahedron. Analogously to an obtuse triangle, the circumcenter is outside of the object for an obtuse tetrahedron.
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of a regular tetrahedron correspond to half of those of a cube: those that map the tetrahedra to themselves, and not to each other. The tetrahedron is the only Platonic solid not mapped to itself by
11529: 4958:, ) can exist if the face or edge marking are included. Tetrahedral diagrams are included for each type below, with edges colored by isometric equivalence, and are gray colored for unique edges. 4150: 4060: 3970: 3794: 3569: 2549: 11928: 9019: 8896: 8155: 5812: 2285: 2280: 2012: 1717: 1191: 955: 657: 10964: 1841:{\displaystyle {\begin{aligned}\arccos \left({\frac {23}{27}}\right)&={\frac {\pi }{2}}-3\arcsin \left({\frac {1}{3}}\right)\\&=3\arccos \left({\frac {1}{3}}\right)-\pi \end{aligned}}} 4243: 11225: 2575:
The proper rotations, (order-3 rotation on a vertex and face, and order-2 on two edges) and reflection plane (through two faces and one edge) in the symmetry group of the regular tetrahedron
6869:{\displaystyle {\begin{cases}\mathbf {a} \cdot \mathbf {b} =ab\cos {\gamma },\\\mathbf {b} \cdot \mathbf {c} =bc\cos {\alpha },\\\mathbf {a} \cdot \mathbf {c} =ac\cos {\beta }.\end{cases}}} 3839: 3712: 9353:{\displaystyle {\begin{aligned}X=(w-U+v)(U+v+w),&\quad x=(U-v+w)(v-w+U),\\Y=(u-V+w)(V+w+u),&\quad y=(V-w+u)(w-u+V),\\Z=(v-W+u)(W+u+v),&\quad z=(W-u+v)\,(u-v+W).\end{aligned}}} 379: 2781:
reflections in a plane combined with 90° rotation about an axis perpendicular to the plane: 3 axes, 2 per axis, together 6; equivalently, they are 90° rotations combined with inversion (
2615: 9460: 4825: 4792: 4759: 4726: 4693: 4660: 4627: 4594: 4535: 4502: 4443: 4410: 4377: 4340: 4285: 8730: 2264: 8004: 6075: 506: 5754: 2538: 3876: 3749: 3639: 3512: 3473: 945: 913: 3241:, which means that the cube can be subdivided into instances of this orthoscheme. If its three perpendicular edges are of unit length, its remaining edges are two of length 5699: 15602:, Dover Publications, 2003 (orig. ed. 1962), p. 107. Note however that Sierpiński repeats an erroneous calculation of the volume of the Heronian tetrahedron example above. 13344: 13334: 13324: 13315: 13305: 13295: 13286: 13266: 13257: 13228: 13218: 13189: 13160: 13150: 13121: 11539: 10635: 6186: 5465: 5455: 5445: 5349: 5339: 5050: 3602: 3337: 3259: 2675: 2476: 2455: 508:. The volume of a regular tetrahedron can be ascertained similarly as the other pyramids, one-third of the base and its height. Because the base is an equilateral, it is: 10578: 4197: 14201:), four hydrogen atoms surround a central carbon or nitrogen atom with tetrahedral symmetry. For this reason, one of the leading journals in organic chemistry is called 13276: 13247: 13237: 13208: 13199: 13179: 13170: 13141: 13131: 10672: 9385:, after Jun Murakami and Masakazu Yano. However, in Euclidean space, scaling a tetrahedron changes its volume but not its dihedral angles, so no such formula can exist. 5359: 5070: 5060: 4910:. Unlike a cylindrical kaleidoscope, Wythoff's mirrors are located at three faces of a Goursat tetrahedron such that all three mirrors intersect at a single point. (The 3385: 3375: 3365: 3357: 3347: 3322:
instances of this same characteristic 3-orthoscheme (just one way, by all of its symmetry planes at once). The characteristic tetrahedron of the cube is an example of a
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as a rectified tetrahedron. The process completes as a birectification, reducing the original faces down to points, and producing the self-dual tetrahedron once again.
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This has two pairs of equal edges (1,3), (2,4) and (1,4), (2,3) but otherwise no edges equal. The only two isometries are 1 and the rotation (12)(34), giving the group
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This has two pairs of equal edges (1,3), (1,4) and (2,3), (2,4) and otherwise no edges equal. The only two isometries are 1 and the reflection (34), giving the group
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Tetrahedra are used in color space conversion algorithms specifically for cases in which the luminance axis diagonally segments the color space (e.g. RGB, CMY).
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to the first), reverse all the signs. These two tetrahedra's vertices combined are the vertices of a cube, demonstrating that the regular tetrahedron is the 3-
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Five tetrahedra are laid flat on a plane, with the highest 3-dimensional points marked as 1, 2, 3, 4, and 5. These points are then attached to each other and
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of the vertex position coordinates of a tetrahedron and its isogonic center are associated, under circumstances analogous to those observed for a triangle.
272:, and correspondingly, a regular octahedron is the result of cutting off, from a regular tetrahedron, four regular tetrahedra of half the linear size (i.e., 4859:. Regular tetrahedra, however, cannot fill space by themselves (moreover, it is not scissors-congruent to any other polyhedra which can fill the space, see 635:{\displaystyle V={\frac {1}{3}}\cdot \left({\frac {\sqrt {3}}{4}}a^{2}\right)\cdot {\frac {\sqrt {6}}{3}}a={\frac {a^{3}}{6{\sqrt {2}}}}\approx 0.118a^{3}.} 15325: 829: 13544: 11706: 10678:
for a tetrahedron, which relates the areas of the faces of the tetrahedron to the dihedral angles about a vertex, is given by the following relation:
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of the twelve-point sphere also lies on the Euler line. Unlike its triangular counterpart, this center lies one third of the way from the Monge point
649:—the angle between two planar—and its angle between lines from the center of a regular tetrahedron between two vertices is respectively: 12417:
A tetrahedron can have integer volume and consecutive integers as edges, an example being the one with edges 6, 7, 8, 9, 10, and 11 and volume 48.
7161:{\displaystyle V={\frac {abc}{6}}{\sqrt {1+2\cos {\alpha }\cos {\beta }\cos {\gamma }-\cos ^{2}{\alpha }-\cos ^{2}{\beta }-\cos ^{2}{\gamma }}},\,} 2895:. When the intersecting plane is near one of the edges the rectangle is long and skinny. When halfway between the two edges the intersection is a 6519:{\displaystyle {\begin{cases}\mathbf {a} =(a_{1},a_{2},a_{3}),\\\mathbf {b} =(b_{1},b_{2},b_{3}),\\\mathbf {c} =(c_{1},c_{2},c_{3}),\end{cases}}} 8470:{\displaystyle V={\frac {abc}{6}}{\sqrt {1+2\cos {\alpha }\cos {\beta }\cos {\gamma }-\cos ^{2}{\alpha }-\cos ^{2}{\beta }-\cos ^{2}{\gamma }}}} 3124:
Kepler's drawing of a regular tetrahedron inscribed in a cube, and one of the four trirectangular tetrahedra that surround it, filling the cube.
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representing the three mirrors. The dihedral angle between each pair of mirrors is encoded in the diagram, as well as the location of a single
4899:. The Goursat tetrahedra generate all the regular polyhedra (and many other uniform polyhedra) by mirror reflections, a process referred to as 2273:
in two ways such that each vertex is a vertex of the cube, and each edge is a diagonal of one of the cube's faces. For one such embedding, the
1699: 14023:(itself is the dual of Szilassi polyhedron) and the tetrahedron are the only two known polyhedra in which every diagonal lies on the sides. 12627: 4946:
The isometries of an irregular (unmarked) tetrahedron depend on the geometry of the tetrahedron, with 7 cases possible. In each case a
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Lindelof, L. (1867). "Sur les maxima et minima d'une fonction des rayons vecteurs menés d'un point mobile à plusieurs centres fixes".
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constant ≈ 1.618, for which Coxeter uses 𝝉 (tau), we reverse Coxeter's conventions, and use 𝝉 to represent the characteristic angle.
10404:{\displaystyle \sin \angle OAB\cdot \sin \angle OBC\cdot \sin \angle OCA=\sin \angle OAC\cdot \sin \angle OCB\cdot \sin \angle OBA.\,} 9004:{\displaystyle {\begin{aligned}p={\sqrt {xYZ}},&\quad q={\sqrt {yZX}},\\r={\sqrt {zXY}},&\quad s={\sqrt {xyz}},\end{aligned}}} 16684: 3389:
by its planes of symmetry. The 24 characteristic tetrahedra of the regular tetrahedron occur in two mirror-image forms, 12 of each.
11389:{\displaystyle {\frac {1}{r_{1}^{2}}}+{\frac {1}{r_{2}^{2}}}+{\frac {1}{r_{3}^{2}}}+{\frac {1}{r_{4}^{2}}}\leq {\frac {2}{r^{2}}},} 6970: 6926: 6882: 17669: 14040:
An irregular volume in space can be approximated by an irregular triangulated surface, and irregular tetrahedral volume elements.
14005:. A stella octangula is a compound of two tetrahedra in dual position and its eight vertices define a cube as their convex hull. 13537: 2721:
rotation about an axis through a vertex, perpendicular to the opposite plane, by an angle of ±120°: 4 axes, 2 per axis, together
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can be grouped into two groups of four, each forming a regular tetrahedron, showing one of the two tetrahedra in the cube. The
1968:{\displaystyle \left(\pm 1,0,-{\frac {1}{\sqrt {2}}}\right)\quad {\mbox{and}}\quad \left(0,\pm 1,{\frac {1}{\sqrt {2}}}\right)} 14019:
and the tetrahedron are the only two known polyhedra in which each face shares an edge with each other face. Furthermore, the
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There are molecules with the shape based on four nearby atoms whose bonds form the sides of a tetrahedral structure, such as
11448: 8320:{\displaystyle {\begin{aligned}X&=b^{2}+c^{2}-x^{2},\\Y&=a^{2}+c^{2}-y^{2},\\Z&=a^{2}+b^{2}-z^{2}.\end{aligned}}} 3201:. A 3-orthoscheme is not a disphenoid, because its opposite edges are not of equal length. It is not possible to construct a 10414:
One may view the two sides of this identity as corresponding to clockwise and counterclockwise orientations of the surface.
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A tetrahedron having stiff edges is inherently rigid. For this reason it is often used to stiffen frame structures such as
13039: 11076:{\displaystyle PA\cdot F_{\mathrm {a} }+PB\cdot F_{\mathrm {b} }+PC\cdot F_{\mathrm {c} }+PD\cdot F_{\mathrm {d} }\geq 9V.} 3807: 3680: 3088: 4883:
For Euclidean 3-space, there are 3 simple and related Goursat tetrahedra. They can be seen as points on and within a cube.
4118: 4028: 3938: 3762: 3537: 3333:. There is a 3-orthoscheme, which is the "characteristic tetrahedron of the regular tetrahedron". The regular tetrahedron 17104: 16298: 15962: 15067: 9610:
of the tetrahedron. Hence there are four medians and three bimedians in a tetrahedron. These seven line segments are all
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The volume of a tetrahedron can be obtained in many ways. It can be given by using the formula of the pyramid's volume:
14036: 2938:, preserving angles but not areas or lengths. Straight lines on the sphere are projected as circular arcs on the plane. 13743: 13530: 4542:
which is one-sixth of a tetrahedron face. The three faces interior to the tetrahedron are: a right triangle with edges
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define a set of parallel planes. When one of these planes intersects the tetrahedron the resulting cross section is a
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The above formula uses six lengths of edges, and the following formula uses three lengths of edges and three angles.
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The absolute value of the scalar triple product can be represented as the following absolute values of determinants:
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together to form a tetrahedron, then the resistance measured between any two vertices is half that of one resistor.
15715: 15340: 13694: 10209: 10194: 9622:). The centroid of a tetrahedron is the midpoint between its Monge point and circumcenter. These points define the 4947: 4864: 4856: 2712: 245:, who associated those four solids with nature. The regular tetrahedron was considered as the classical element of 13942: 9577:
and points such as a centroid. However, there is generally no orthocenter in the sense of intersecting altitudes.
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are the lengths of the tetrahedron's edges as in the following image. Here, the first three form a triangle, with
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Tetrahedra which do not have four equilateral faces are categorized and named by the symmetries they do possess.
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Leung, Kam-tim; and Suen, Suk-nam; "Vectors, matrices and geometry", Hong Kong University Press, 1994, pp. 53–54
14939: 13956: 222:. In other words, all of its faces are the same size and shape (congruent) and all edges are the same length. A 16007: 15993: 15023: 14997: 14877: 14779: 14152: 14069: 9435: 1872:, defining the four vertices of a tetrahedron with edge length 2, centered at the origin, and two-level edges: 12357: 6146:{\textstyle {\frac {1}{6}}\det(\mathbf {a} -\mathbf {d} ,\mathbf {b} -\mathbf {d} ,\mathbf {c} -\mathbf {d} )} 3486: 3447: 299: 129:(any of the four faces can be considered the base), so a tetrahedron is also known as a "triangular pyramid". 17706: 16596: 15251: 14893: 13736: 10440: 10239: 9637:
of the general triangle has an analogue in the circumsphere of a tetrahedron's medial tetrahedron. It is the
7471: 4799: 4766: 4733: 4700: 4667: 4634: 4601: 4568: 4509: 4476: 4417: 4384: 4351: 4314: 4259: 125:
base and triangular faces connecting the base to a common point. In the case of a tetrahedron, the base is a
12386:. One example has one edge of 896, the opposite edge of 990 and the other four edges of 1073; two faces are 9641:
and besides the centroids of the four faces of the reference tetrahedron, it passes through four substitute
3029:
by these chains, which become periodic in the three-dimensional space of the 4-polytope's boundary surface.
2423:{\displaystyle {\begin{aligned}(1,1,1),&\quad (1,-1,-1),\\(-1,1,-1),&\quad (-1,-1,1).\end{aligned}}} 17711: 17701: 15674: 15168: 14638: 14475: 14073: 6154: 5417:
It has 4 isometries. The isometries are 1 and the 180° rotations (12)(34), (13)(24), (14)(23). This is the
4935: 4255:
If the regular tetrahedron has edge length 𝒍 = 2, its characteristic tetrahedron's six edges have lengths
2233: 16890: 16831: 15314:. Dept of Mathematics, Chulalongkorn University, Bangkok. Archived from the original on 27 February 2009. 13970: 13948: 3582: 3202: 2506: 479: 9381:
of the tetrahedron determine its shape and hence its volume. In these cases, the volume is given by the
4180: 3852: 3725: 3615: 17696: 16920: 16880: 16486: 16032: 15783:
Vestiges of the Molten Globe, as exhibited in the figure of the earth, volcanic action and physiography
15569: 14750: 14689: 13998: 13962: 13902: 12613: 10200:
On otherhand, several irregular tetrahedra are known, of which copies can tile space, for instance the
9463: 4860: 3129: 3115: 2999: 2983: 307: 10189:
claimed it was possible. However, two regular tetrahedra can be combined with an octahedron, giving a
3102:
has concurrent cevians that join the vertices to the points of contact of the opposite faces with the
921: 889: 16915: 16910: 14610: 14257: 13689: 13684: 11653:{\displaystyle V={\frac {1}{3}}A_{1}r+{\frac {1}{3}}A_{2}r+{\frac {1}{3}}A_{3}r+{\frac {1}{3}}A_{4}r} 9664:
The radius of the twelve-point sphere is one third of the circumradius of the reference tetrahedron.
9382: 6240:{\displaystyle 6\cdot V={\begin{Vmatrix}\mathbf {a} &\mathbf {b} &\mathbf {c} \end{Vmatrix}}} 2584: 469:{\displaystyle A=4\cdot \left({\frac {\sqrt {3}}{4}}a^{2}\right)=a^{2}{\sqrt {3}}\approx 1.732a^{2}.} 6740: 6339: 17691: 17127: 16480: 16011: 15997: 14614: 14470: 14264: 13714:
The tetrahedron is topologically related to a series of regular polyhedra and tilings with order-3
12872: 12867: 12382:
There exist tetrahedra having integer-valued edge lengths, face areas and volume. These are called
9588: 5672: 3069: 2965: 2931: 2711:(in parentheses are given the permutations of the vertices, or correspondingly, the faces, and the 273: 246: 15613: 14320:
of four, the tetrahedral shape of the four chemical bonds in silicon is a strong influence on how
10610: 3146:
discovered the relationship between the cube, regular tetrahedron and trirectangular tetrahedron.
2658: 2433: 17097: 17021: 17016: 16895: 16801: 16608: 16536: 16456: 16291: 15913: 15849: 14856: 14551: 14541: 14484: 14313: 14061: 14020: 12885: 12877: 10556: 9619: 9618:
of the tetrahedron. In addition the four medians are divided in a 3:1 ratio by the centroid (see
2960: 2817: 2561: 15120:"Finite number of similarity classes in Longest Edge Bisection of nearly equilateral tetrahedra" 14694: 12742: 10640: 9392:, and the distance between the edges is defined as the distance between the two skew lines. Let 3209: 311: 16885: 16826: 16816: 16761: 16542: 15825: 15777: 15593: 14606: 14406: 14402: 14396: 13977:
of five tetrahedra has been known for hundreds of years. It comes up regularly in the world of
13928: 12862: 10087:
found that, corresponding to any given tetrahedron is a point now known as an isogonic center,
8881:{\displaystyle V={\frac {\sqrt {\,(-p+q+r+s)\,(p-q+r+s)\,(p+q-r+s)\,(p+q+r-s)}}{192\,u\,v\,w}}} 7847: 7470:
Given the distances between the vertices of a tetrahedron the volume can be computed using the
6314:{\displaystyle 6\cdot V={\begin{Vmatrix}\mathbf {a} \\\mathbf {b} \\\mathbf {c} \end{Vmatrix}}} 4911: 3006: 2466: 291:, a regular tetrahedron with four triangular pyramids attached to each of its faces. i.e., its 15897: 14887: 4986: 4906:
For polyhedra, Wythoff's construction arranges three mirrors at angles to each other, as in a
17641: 17634: 17627: 16905: 16821: 16776: 16264: 16259: 15893: 15598: 15490: 15178: 15162: 14949: 14521: 14203: 14162: 14081: 13367: 13357: 12679: 8140:{\displaystyle V={\frac {\sqrt {4a^{2}b^{2}c^{2}-a^{2}X^{2}-b^{2}Y^{2}-c^{2}Z^{2}+XYZ}}{12}}} 7851: 5307: 4078: 3988: 3898: 2915: 2803: 2274: 1869: 284: 280: 41: 17166: 17144: 17132: 15853: 15243: 17298: 17245: 16865: 16791: 16739: 16184: 15787: 15648: 15381: 14744: 14724: 14561: 14089: 13482: 13382: 13050: 12795: 12671: 12661: 12383: 12377: 10583: 10529: 10502: 10475: 10448: 10182: 4926: 4900: 4855:
A disphenoid can be a space-filling tetrahedron in the directly congruent sense, as in the
3323: 2871: 2683: 2627: 1159: 916: 261: 219: 10226: 9362:
Any plane containing a bimedian (connector of opposite edges' midpoints) of a tetrahedron
4450:
of the regular tetrahedron). The 3-edge path along orthogonal edges of the orthoscheme is
8: 17716: 17686: 17653: 17552: 17302: 17031: 16900: 16875: 16860: 16796: 16744: 16201: 15471: 15057: 15055: 14933: 14739: 14531: 14317: 14016: 13974: 13500:
This polyhedron is topologically related as a part of sequence of regular polyhedra with
13487: 13472: 13462: 12666: 10175: 10091:, at which the solid angles subtended by the faces are equal, having a common value of π 9667:
There is a relation among the angles made by the faces of a general tetrahedron given by
4896: 3221: 1857: 288: 257: 15791: 15652: 14903: 1984: 17522: 17472: 17422: 17379: 17349: 17309: 17272: 17090: 17046: 17011: 16870: 16765: 16714: 16653: 16530: 16524: 16284: 16193: 16075: 16067: 16017: 15818: 15398: 15319: 15278: 15260: 14734: 14571: 14093: 14065: 14045: 12996: 12600: 12457: 12426: 12387: 10220: 9469: 9415: 9395: 8710: 8690: 8670: 8650: 8630: 8610: 8590: 8570: 8550: 8530: 8510: 8490: 7984: 7964: 7944: 7924: 7904: 7884: 7864: 7855: 5783: 5759: 5498: 5397: 4888: 4849: 4546: 4454: 4292: 3652: 3419: 3010: 2952: 1139: 1119: 866: 843: 359: 339: 303: 118: 104: 15931: 15190: 15083: 15052: 13501: 10084: 5075: 3198: 3018: 3014: 2501: 17661: 17026: 16836: 16811: 16755: 16643: 16567: 16519: 16492: 16462: 16269:
that also includes a description of a "rotating ring of tetrahedra", also known as a
16242: 16219: 16172: 16094: 16079: 16036: 15966: 15928: 15829: 15795: 15752: 15619: 15433: 15376: 15141: 15044: 15027: 14831: 14775: 14594: 14451: 14422: 14085: 14009: 13892: 13679: 13387: 13026: 12968: 12961: 12462: 12368:
The sum of the areas of any three faces is greater than the area of the fourth face.
9634: 9374: 5114: 4996: 4539: 3022: 2678: 1678: 100: 89: 12975: 10637:
be the dihedral angle between the two faces of the tetrahedron adjacent to the edge
5277:. An irregular tetrahedron has Schläfli symbol ( )∨( )∨( )∨( ). 17665: 17230: 17219: 17208: 17197: 17188: 17179: 17118: 17114: 16965: 16648: 16628: 16450: 16162: 16126: 16059: 15909: 15656: 15552: 15425: 15416:
Rassat, André; Fowler, Patrick W. (2004). "Is There a "Most Chiral Tetrahedron"?".
15390: 15270: 15131: 15039: 14729: 14581: 14409:
to explain the formation of the Earth, was popular through the early 20th century.
14357: 14002: 13934: 13897: 13887: 13509: 12954: 12940: 12656: 11859:{\displaystyle R={\frac {\sqrt {(aA+bB+cC)(aA+bB-cC)(aA-bB+cC)(-aA+bB+cC)}}{24V}}.} 10160: 10108: 10080: 9611: 9370: 8487:
The volume of a tetrahedron can be ascertained by using the Heron formula. Suppose
5532: 5418: 4991: 3103: 3092: 2927: 2900: 315: 238: 187: 137: 133: 16109: 15477: 8479: 197: 17255: 17240: 16602: 16514: 16509: 16474: 16429: 16419: 16409: 16404: 16245: 16180: 16122: 16088: 15781: 14834: 14602: 14466: 14376: 14372: 12777: 12763: 12435: 12353: 10164: 5777: 5586: 5140: 5044: 5033: 4845: 3143: 3120: 2708: 2622: 2565: 2470: 2458: 2270: 1674: 253: 241:. Known since antiquity, the Platonic solid is named after the Greek philosopher 93: 85: 81: 16026: 15854:"William Lowthian Green and his Theory of the Evolution of the Earth's Features" 14375:, with the number rolled appearing around the bottom or on the top vertex. Some 14140: 13782: 12770: 10426:
triangles, there are four such constraints on sums of angles, and the number of
6177:
of the volume of any parallelepiped that shares three converging edges with it.
5580: 5313: 4922:
which is multiplied by mirror reflections into the vertices of the polyhedron.)
4879: 2906: 2571: 2548: 17605: 16786: 16709: 16658: 16561: 16424: 16414: 16167: 16150: 16111:
What has the Volume of a Tetrahedron to do with Computer Programming Languages?
14802:𝟀, 𝝓, 𝟁 of a regular polytope. Because 𝝓 is commonly used to represent the 14662: 14658: 14642: 13765: 12749: 12572: 12558: 12452: 10675: 9574: 9378: 6158: 5001: 3238: 3165: 2580: 646: 310:, which is a tessellation. Some tetrahedra that are not regular, including the 249:, because of his interpretation of its sharpest corner being most penetrating. 234: 204: 15136: 15119: 14253:
of mixtures of chemical substances are represented graphically as tetrahedra.
14012:
is another polyhedron with four faces, but it does not have triangular faces.
12947: 12565: 10115:, of the vertices. In the event that the solid angle at one of the vertices, 5504: 5263: 5012: 230:. There are eight convex deltahedra, one of which is the regular tetrahedron. 17680: 17622: 17510: 17503: 17496: 17460: 17453: 17446: 17410: 17403: 16991: 16847: 16781: 16579: 16573: 16468: 16399: 16389: 16176: 15871: 15813: 15145: 14704: 14598: 14480: 14309: 14250: 14208: 14158: 13715: 13377: 13110: 13103: 12847: 12830: 12827:
A regular tetrahedron can be seen as a degenerate polyhedron, a uniform dual
12756: 12544: 9580: 6153:, or any other combination of pairs of vertices that form a simply connected 5510: 5403: 5274: 4892: 3065: 2935: 2810: 2462: 1853: 180: 15556: 13609: 13096: 13082: 13068: 12988: 12537: 3160: 3050: 3041: 136:, a tetrahedron can be folded from a single sheet of paper. It has two such 17562: 16394: 16270: 15799: 15437: 15429: 14803: 14618: 14350: 14272: 14077: 14053: 13994: 13990: 13982: 13882: 13810: 13789: 13602: 13492: 13089: 13075: 13061: 12981: 12920: 12913: 12551: 10245: 10190: 9606:
and a line segment joining the midpoints of two opposite edges is called a
5612: 5208: 4907: 4841: 838: 144: 31: 12927: 2755:
rotation by an angle of 180° such that an edge maps to the opposite edge:
168: 17571: 17532: 17482: 17432: 17389: 17359: 16434: 16368: 16358: 16348: 14755: 14718: 14650: 14384: 14368: 14364: 14333: 14288: 14284: 14145: 14049: 14048:, complicated three-dimensional shapes are commonly broken down into, or 13986: 13674: 6070: 4848:, a family of space-filling tetrahedra. All space-filling tetrahedra are 3217: 3137: 3072:. When only one pair of opposite edges are perpendicular, it is called a 2618: 1978: 1706: 227: 14431: 13803: 13796: 13595: 13588: 13581: 12906: 12899: 12584:
A regular tetrahedron can be seen as a degenerate polyhedron, a uniform
9558:{\displaystyle V={\frac {d|(\mathbf {a} \times \mathbf {(b-c)} )|}{6}}.} 7854:
in the 15th century, as a three-dimensional analogue of the 1st century
2945: 2789:): the rotations correspond to those of the cube about face-to-face axes 17557: 17541: 17491: 17441: 17398: 17368: 17282: 17056: 16944: 16734: 16701: 16619: 16373: 16363: 16353: 16338: 16328: 16307: 16071: 15639:
Brittin, W. E. (1945). "Valence angle of the tetrahedral carbon atom".
15402: 15282: 14634: 14105: 14057: 13867: 13669: 13362: 13030: 12892: 12711: 12649: 12642: 10227:
A law of sines for tetrahedra and the space of all shapes of tetrahedra
9627: 9389: 5653:
computer graphics. One of the commonly used subdivision methods is the
5299: 4868: 3173: 3155: 642:
Its volume can also be obtained by dissecting a cube into three parts.
269: 223: 77: 35: 15660: 15118:
Trujillo-Pino, Agustín; Suárez, Jose Pablo; Padrón, Miguel A. (2024).
13435: 12718: 12525: 10178:
gives two more regular compounds, containing five and ten tetrahedra.
226:
polyhedron in which all of its faces are equilateral triangles is the
17613: 17527: 17477: 17427: 17384: 17354: 17323: 17051: 17041: 16986: 16970: 16806: 16633: 16250: 15936: 14839: 14166: 13442: 13421: 13407: 13025:
A truncation process applied to the tetrahedron produces a series of
12787: 12697: 12607: 12587: 12511: 12490: 10186: 10092: 9363: 3164:
A space-filling tetrahedral disphenoid inside a cube. Two edges have
2892: 2707:—the identity and 11 proper rotations—with the following 1868:
One way to construct a regular tetrahedron is by using the following
1849: 884: 16063: 15394: 15274: 14128: 14072:. These methods have wide applications in practical applications in 13838: 13817: 13630: 13574: 12690: 12518: 3185: 2978: 2793: 17587: 17342: 17338: 17265: 16937: 16669: 16333: 15517: 14488: 14380: 14346: 14294: 14186: 14133: 14117: 13859: 13852: 13845: 13659: 13651: 13644: 13637: 12704: 12442: 11240: 10099:
lies inside the tetrahedron, and because the sum of distances from
9599: 6157:. Comparing this formula with that used to compute the volume of a 5187: 4867:
fills space with alternating regular tetrahedron cells and regular
3329:
Every regular polytope, including the regular tetrahedron, has its
3026: 2987: 2910:
A tetragonal disphenoid viewed orthogonally to the two green edges.
1686: 861: 292: 148: 126: 53: 15265: 15104:, p. 63, §4.3 Rotation groups in two dimensions; notion of a 14672: 14360:, dating from 2600 BC, was played with a set of tetrahedral dice. 13623: 9583:
found a center that exists in every tetrahedron, now known as the
3361:
is subdivided into 24 instances of its characteristic tetrahedron
2839: 17596: 17566: 17333: 17328: 17319: 17260: 17061: 17036: 16638: 15980:
Bottema, O. (1969). "A Theorem of Bobillier on the Tetrahedron".
14708: 14699: 14321: 14305: 14170: 13978: 12504: 10156: 5273:
Its only isometry is the identity, and the symmetry group is the
3213: 152: 122: 107: 15959:
A Mathematical Space Odyssey: Solid Geometry in the 21st Century
13616: 9412:
be the distance between the skew lines formed by opposite edges
5701:, the iterated LEB produces no more than 37 similarity classes. 4343:
around its exterior right-triangle face (the edges opposite the
3255:, so all its edges are edges or diagonals of the cube. The cube 1183:
from an arbitrary point in 3-space to its four vertices, it is:
306:
in the ratio of two tetrahedra to one octahedron, they form the
174:
Regular tetrahedron, described as the classical element of fire.
17536: 17486: 17436: 17393: 17363: 17314: 17250: 15611: 14916: 14914: 14912: 14798:) uses the greek letter 𝝓 (phi) to represent one of the three 14637:
of the tetrahedron (comprising the vertices and edges) forms a
14513: 14298: 13449: 3084: 2995: 2896: 2880: 2846: 15860:. Vol. XXV. Geological Publishing Company. pp. 1–10. 13831: 13824: 13428: 13400: 12725: 12497: 9567: 7981:
be those of the opposite edges. The volume of the tetrahedron
5541:. A digonal disphenoid has Schläfli symbol { }∨{ }. 2457:, centered at the origin. For the other tetrahedron (which is 327: 16136:
Lee, Jung Rye (1997). "The Law of Cosines in a Tetrahedron".
14230: 14211:
between any two vertices of a perfect tetrahedron is arccos(−
13414: 12592: 11684:
be the lengths of the three edges that meet at a vertex, and
10185:
by themselves, although this result seems likely enough that
6069:
The volume of a tetrahedron can be ascertained in terms of a
1652: 242: 16276: 16216:
The Routledge International Handbook of Innovation Education
14909: 14641:, with 4 vertices, and 6 edges. It is a special case of the 14001:, in which the ten tetrahedra are arranged as five pairs of 7004:{\displaystyle c={\begin{Vmatrix}\mathbf {c} \end{Vmatrix}}} 6960:{\displaystyle b={\begin{Vmatrix}\mathbf {b} \end{Vmatrix}}} 6916:{\displaystyle a={\begin{Vmatrix}\mathbf {a} \end{Vmatrix}}} 17286: 16729: 16260:
Free paper models of a tetrahedron and many other polyhedra
15519:
Spherical Trigonometry: For the Use of Colleges and Schools
13877: 13467: 11126:
to the faces, and suppose the faces have equal areas, then
9656:
towards the circumcenter. Also, an orthogonal line through
7191:, is the angle between the two edges connecting the vertex 6862: 6512: 6161:, we conclude that the volume of a tetrahedron is equal to 2557: 15926: 15244:"Altitudes of a tetrahedron and traceless quadratic forms" 14169:) at the four corners of a tetrahedron. For instance in a 9598:
A line segment joining a vertex of a tetrahedron with the
4925:
Among the Goursat tetrahedra which generate 3-dimensional
3064:
If all three pairs of opposite edges of a tetrahedron are
1981:, centroid at the origin, with lower face parallel to the 147:) on which all four vertices lie, and another sphere (the 16151:"On the volume of a hyperbolic and spherical tetrahedron" 15341:"Déterminants sphérique et hyperbolique de Cayley-Menger" 15117: 14790: 14788: 14271:-butyltetrahedrane, known derivative of the hypothetical 11399:
with equality if and only if the tetrahedron is regular.
5150:. A triangular pyramid has Schläfli symbol {3}∨( ). 279:
The tetrahedron is yet related to another two solids: By
15742:"Radial and Pruned Tetrahedral Interpolation Techniques" 15223: 14442: 14260:
are represented graphically on a two-dimensional plane.
12834:, containing 6 vertices, in two sets of colinear edges. 12352:
The tetrahedron's center of mass can be computed as the
10232: 7921:
be the lengths of three edges that meet at a point, and
233:
The regular tetrahedron is also one of the five regular
15872:"Marvin Minsky: Stanley Kubrick Scraps the Tetrahedron" 15618:, U. S. Government Printing Office, p. 13-10, 15543:
centroidal Voronoi tessellation and its applications",
11524:{\displaystyle r={\frac {3V}{A_{1}+A_{2}+A_{3}+A_{4}}}} 9466:. Then another formula for the volume of a tetrahedron 3311:
four different ways, with all six surrounding the same
2866: 2579:
The regular tetrahedron has 24 isometries, forming the
237:, a set of polyhedrons in which all of their faces are 15201: 15199: 14785: 14747:– constructed by joining two tetrahedra along one face 12161: 11982: 9682: 7508: 7269: 6985: 6941: 6897: 6567: 6277: 6207: 6078: 5804:
Given the vertices of a tetrahedron in the following:
4805: 4772: 4739: 4706: 4673: 4640: 4607: 4574: 4515: 4482: 4423: 4390: 4357: 4320: 4265: 4217: 4124: 4034: 3944: 3857: 3812: 3768: 3730: 3685: 3620: 3543: 3318:
cube diagonal. The cube can also be dissected into 48
3189:
A cube dissected into six characteristic orthoschemes.
2236: 1921: 482: 207:
is left, where the five edge angles do not quite meet.
143:
For any tetrahedron there exists a sphere (called the
92:. The tetrahedron is the simplest of all the ordinary 15004: 11926: 11709: 11542: 11451: 11265: 11135: 10967: 10684: 10643: 10613: 10586: 10559: 10532: 10505: 10478: 10451: 10273: 9676: 9492: 9472: 9438: 9418: 9398: 9017: 8894: 8733: 8713: 8693: 8673: 8653: 8633: 8613: 8593: 8573: 8553: 8533: 8513: 8493: 8333: 8153: 8007: 7987: 7967: 7947: 7927: 7907: 7887: 7867: 7483: 7243: 7020: 6973: 6929: 6885: 6734: 6542: 6333: 6259: 6189: 5810: 5786: 5762: 5720: 5675: 5647: 5493:
Generalized disphenoids (2 pairs of equal triangles)
4941: 4802: 4769: 4736: 4703: 4670: 4637: 4604: 4571: 4549: 4512: 4479: 4457: 4420: 4387: 4354: 4317: 4295: 4262: 4215: 4183: 4121: 4081: 4031: 3991: 3941: 3901: 3855: 3810: 3765: 3728: 3683: 3655: 3618: 3585: 3540: 3489: 3450: 3422: 3055:
Tetrahedral symmetries shown in tetrahedral diagrams
2686: 2661: 2630: 2592: 2509: 2436: 2283: 2010: 1987: 1878: 1715: 1189: 1162: 1142: 1122: 953: 924: 892: 869: 846: 833:
Regular tetrahedron ABCD and its circumscribed sphere
655: 514: 382: 362: 342: 16240: 14829: 10930:, and for which the areas of the opposite faces are 4936:
dissected into characteristic tetrahedra of the cube
4145:{\displaystyle {\sqrt {\tfrac {1}{6}}}\approx 0.408} 4055:{\displaystyle {\sqrt {\tfrac {1}{2}}}\approx 0.707} 3965:{\displaystyle {\sqrt {\tfrac {3}{2}}}\approx 1.225} 3789:{\displaystyle {\sqrt {\tfrac {1}{3}}}\approx 0.577} 3564:{\displaystyle {\sqrt {\tfrac {4}{3}}}\approx 1.155} 2994:
Regular tetrahedra can be stacked face-to-face in a
336:
Given that the regular tetrahedron with edge length
15389:(5). Mathematical Association of America: 227–243. 15211: 15196: 15191:"Simplex Volumes and the Cayley-Menger Determinant" 13981:. Joining the twenty vertices would form a regular 9388:Any two opposite edges of a tetrahedron lie on two 3233:tetrahedron because it contains four right angles. 3168:
of 90°, and four edges have dihedral angles of 60°.
376:is four times the area of an equilateral triangle: 16266:An Amazing, Space Filling, Non-regular Tetrahedron 15817: 15491:"Einige Bemerkungen über die dreiseitige Pyramide" 13969:An interesting polyhedron can be constructed from 12425:A regular tetrahedron can be seen as a triangular 12420: 12333: 11858: 11652: 11523: 11388: 11219: 11075: 10891: 10666: 10629: 10599: 10572: 10545: 10518: 10491: 10464: 10403: 10050: 9557: 9478: 9454: 9424: 9404: 9352: 9003: 8880: 8719: 8699: 8679: 8659: 8639: 8619: 8599: 8579: 8559: 8539: 8519: 8499: 8469: 8319: 8139: 7993: 7973: 7953: 7933: 7913: 7893: 7873: 7796: 7459: 7160: 7003: 6959: 6915: 6868: 6714: 6518: 6313: 6239: 6145: 6061: 5792: 5768: 5748: 5693: 4840:packs with directly congruent or enantiomorphous ( 4819: 4786: 4753: 4720: 4687: 4654: 4621: 4588: 4555: 4529: 4496: 4463: 4437: 4404: 4371: 4334: 4301: 4279: 4237: 4191: 4144: 4104: 4054: 4014: 3964: 3924: 3870: 3833: 3788: 3743: 3706: 3661: 3633: 3596: 3563: 3506: 3467: 3428: 2778:reflections in a plane perpendicular to an edge: 6 2699: 2669: 2643: 2609: 2532: 2449: 2422: 2258: 2222: 1996: 1967: 1840: 1641: 1175: 1148: 1128: 1108: 939: 907: 875: 852: 819: 634: 500: 468: 368: 348: 260:figure comprising two such dual tetrahedra form a 252:The regular tetrahedron is self-dual, meaning its 16138:J. Korea Soc. Math. Educ. Ser. B: Pure Appl. Math 15495:Sammlung mathematischer Aufsätze u. Bemerkungen 1 15092:, pp. 33–34, §3.1 Congruent transformations. 15064:, pp. 71–72, §4.7 Characteristic tetrahedra. 10910:be any interior point of a tetrahedron of volume 9534: 9522: 2794:Orthogonal projections of the regular tetrahedron 17678: 15324:: CS1 maint: bot: original URL status unknown ( 15076:, pp. 292–293, Table I(i); "Tetrahedron, 𝛼 14978: 14865: 13997:of each other. Superimposing both forms gives a 10434: 10417:Putting any of the four vertices in the role of 7261: 6089: 4238:{\displaystyle {\tfrac {{\text{arc sec }}3}{2}}} 15852:(January 1900). Winchell, Newton Horace (ed.). 15444: 14855:Ford, Walter Burton; Ammerman, Charles (1913), 14060:in the process of setting up the equations for 13029:. Truncating edges down to points produces the 11220:{\displaystyle PA+PB+PC+PD\geq 3(PJ+PK+PL+PM).} 5335:. A tetragonal disphenoid has Coxeter diagram 2887:The two skew perpendicular opposite edges of a 2269:A regular tetrahedron can be embedded inside a 14278: 12397:and the other two are isosceles with areas of 3834:{\displaystyle {\tfrac {\pi }{2}}-{\text{𝜿}}} 3707:{\displaystyle {\tfrac {\pi }{2}}-{\text{𝜿}}} 3283:can be dissected into six such 3-orthoschemes 3205:with right triangle or obtuse triangle faces. 17098: 16685: 16292: 15898:"The tetrahedral principle in kite structure" 15497:(in German). Berlin: Maurer. pp. 105–132 14324:of silicon form and what shapes they assume. 13744: 13538: 12621: 10212:. The complete list remains an open problem. 7219:, is defined by the position of the vertices 3109: 2926:The tetrahedron can also be represented as a 218:is a tetrahedron in which all four faces are 16148: 15956: 15914:10.1038/scientificamerican06131903-22947supp 15632: 15415: 15241: 15229: 15158: 14945: 14854: 14778:at a vertex. In chemistry, it is called the 13522:32 symmetry mutation of regular tilings: {3, 12310: 12296: 12284: 12270: 12257: 12243: 12231: 12217: 12204: 12190: 12178: 12164: 11917:can be formulated as matrix-vector product: 11668:Denote the circumradius of a tetrahedron as 11438:denote the area of each faces, the value of 10171:added to make a cube, which has 8 vertices. 9626:of the tetrahedron that is analogous to the 5441:. A rhombic disphenoid has Coxeter diagram 2918:when applied to the two special edge pairs. 2527: 2515: 356:. The surface area of a regular tetrahedron 16128:Harmonices Mundi (The Harmony of the World) 14379:-like puzzles are tetrahedral, such as the 14157:The tetrahedron shape is seen in nature in 10131:. If however, a tetrahedron has a vertex, 9568:Properties analogous to those of a triangle 4914:of the generated polyhedron contains three 4831: 3395:Characteristics of the regular tetrahedron 2610:{\displaystyle \mathrm {T} _{\mathrm {d} }} 2430:This yields a tetrahedron with edge-length 1977:Expressed symmetrically as 4 points on the 1693:to a vertex of the base is twice that from 1116:For a regular tetrahedron with side length 17105: 17091: 16692: 16678: 16299: 16285: 15615:Pilot's Handbook of Aeronautical Knowledge 15587: 13751: 13737: 13728:32 symmetry mutation of regular tilings: { 13545: 13531: 12628: 12614: 11235:Denoting the inradius of a tetrahedron as 3197:is a tetrahedron where all four faces are 3036: 16213: 16166: 15848: 15786:. Vol. Part I. London: E. Stanford. 15515: 15308:The Various Kinds of Centres of Simplices 15264: 15135: 15043: 14883: 14099: 10400: 10174:Inscribing tetrahedra inside the regular 10047: 9455:{\displaystyle \mathbf {b} -\mathbf {c} } 9321: 8871: 8867: 8863: 8830: 8802: 8774: 8743: 7453: 7183:are the plane angles occurring in vertex 7157: 1136:, the radius of its circumscribed sphere 16724: 16024: 15612:Federal Aviation Administration (2009), 15379:(1981). "Which tetrahedra fill space?". 15375: 15356: 14899: 14345: 14144:Calculation of the central angle with a 14139: 14127: 14035: 11700:be the volume of the tetrahedron. Then 10580:be the area of the face opposite vertex 8478: 4878: 3407: 3404: 3184: 3159: 3119: 3046:Tetrahedral symmetry subgroup relations 2977: 2905: 2870: 2570: 2547: 1863: 828: 325: 17670:List of regular polytopes and compounds 16155:Communications in Analysis and Geometry 16050:Cundy, H. Martyn (1952). "Deltahedra". 16006: 15992: 15979: 15739: 15638: 15533: 15465: 15463: 15461: 15459: 15217: 15101: 15089: 15073: 15061: 15022: 14970: 14964: 14920: 14795: 13040:Family of uniform tetrahedral polyhedra 11696:the length of the opposite edges. Let 10248:is that in a tetrahedron with vertices 6529:are expressed as row or column vectors. 4820:{\displaystyle {\sqrt {\tfrac {1}{6}}}} 4787:{\displaystyle {\sqrt {\tfrac {3}{2}}}} 4754:{\displaystyle {\sqrt {\tfrac {4}{3}}}} 4721:{\displaystyle {\sqrt {\tfrac {1}{6}}}} 4688:{\displaystyle {\sqrt {\tfrac {1}{2}}}} 4655:{\displaystyle {\sqrt {\tfrac {1}{3}}}} 4622:{\displaystyle {\sqrt {\tfrac {1}{2}}}} 4589:{\displaystyle {\sqrt {\tfrac {3}{2}}}} 4530:{\displaystyle {\sqrt {\tfrac {1}{6}}}} 4497:{\displaystyle {\sqrt {\tfrac {1}{3}}}} 4438:{\displaystyle {\sqrt {\tfrac {1}{6}}}} 4405:{\displaystyle {\sqrt {\tfrac {1}{2}}}} 4372:{\displaystyle {\sqrt {\tfrac {3}{2}}}} 4335:{\displaystyle {\sqrt {\tfrac {1}{3}}}} 4280:{\displaystyle {\sqrt {\tfrac {4}{3}}}} 3032: 3025:) can be constructed as tilings of the 2655:It has rotational tetrahedral symmetry 476:The height of a regular tetrahedron is 14: 17679: 16149:Murakami, Jun; Yano, Masakazu (2005). 16121: 16086: 15812: 15488: 15304: 15174: 15010: 14483:, a cognitive scientist and expert on 14256:However, quaternary phase diagrams in 10202:characteristic orthoscheme of the cube 10150: 10135:, with solid angle greater than π sr, 5591: 5515: 5408: 5318: 5268: 5192: 5119: 5017: 4887:An irregular tetrahedron which is the 4874: 2651:. They can be categorized as follows: 2259:{\textstyle {\frac {2{\sqrt {6}}}{3}}} 1677:along an edge is twice that along the 1673:distance covered from the base to the 1669:), corresponding to the fact that the 158: 103:case of the more general concept of a 16673: 16280: 16241: 16107: 16049: 15927: 15776: 15698: 15338: 15242:Havlicek, Hans; Weiß, Gunter (2003). 15205: 14871: 14830: 14031: 12371: 5704: 2930:, and projected onto the plane via a 302:(fill space), but if alternated with 16699: 16191: 15892: 15456: 15359:Acta Societatis Scientiarum Fennicae 14984: 14825: 14823: 14499: 10553:be the points of a tetrahedron. Let 10219:The tetrahedron is unique among the 7850:, is essentially due to the painter 4901:Wythoff's kaleidoscopic construction 2867:Cross section of regular tetrahedron 501:{\textstyle {\frac {\sqrt {6}}{3}}a} 256:is another regular tetrahedron. The 121:, which is a polyhedron with a flat 16135: 15963:Mathematical Association of America 15450: 15124:Applied Mathematics and Computation 10422:the result is the fourth identity. 10216:tetrahedron have the same volume.) 5749:{\displaystyle V={\frac {1}{3}}Ah.} 2973: 2921: 2533:{\displaystyle \mathrm {h} \{4,3\}} 1709:at a vertex subtended by a face is 1651:With respect to the base plane the 61: 24: 16316:Listed by number of faces and type 15957:Alsina, C.; Nelsen, R. B. (2015). 14479:to be a tetrahedron, according to 14412: 14165:atoms are surrounded by atoms (or 14094:naval architecture and engineering 12591:, where base polygons are reduced 11055: 11031: 11007: 10983: 10858: 10848: 10816: 10806: 10774: 10764: 10740: 10722: 10704: 10686: 10561: 10385: 10364: 10343: 10322: 10301: 10280: 5648:Subdivision and similarity classes 4950:is formed. Two other isometries (C 4942:Isometries of irregular tetrahedra 4729:, and a right triangle with edges 3871:{\displaystyle {\tfrac {\pi }{3}}} 3744:{\displaystyle {\tfrac {\pi }{3}}} 3634:{\displaystyle {\tfrac {\pi }{3}}} 2990:, seen in stereographic projection 2663: 2601: 2595: 2511: 1078: 1032: 931: 899: 25: 17728: 16234: 15751:. HPL-98-95: 1–32. Archived from 14820: 10901: 10223:in possessing no parallel faces. 10201: 9602:of the opposite face is called a 5198:triangles with a common base edge 3507:{\displaystyle \pi -2{\text{𝟁}}} 3468:{\displaystyle \pi -2{\text{𝜿}}} 2677:. This symmetry is isomorphic to 332:3D model of a regular tetrahedron 15534:Lévy, Bruno; Liu, Yang (2010), " 15305:Outudee, Somluck; New, Stephen. 14936:, Mathematische Basteleien, 2001 14671: 14512: 14450: 14441: 14430: 14421: 13955: 13941: 13927: 13858: 13851: 13844: 13837: 13830: 13823: 13816: 13809: 13802: 13795: 13788: 13781: 13650: 13643: 13636: 13629: 13622: 13615: 13608: 13601: 13594: 13587: 13580: 13573: 13448: 13441: 13434: 13427: 13420: 13413: 13406: 13399: 13342: 13337: 13332: 13327: 13322: 13313: 13308: 13303: 13298: 13293: 13284: 13279: 13274: 13269: 13264: 13255: 13250: 13245: 13240: 13235: 13226: 13221: 13216: 13211: 13206: 13197: 13192: 13187: 13182: 13177: 13168: 13163: 13158: 13153: 13148: 13139: 13134: 13129: 13124: 13119: 13109: 13102: 13095: 13088: 13081: 13074: 13067: 13060: 12987: 12974: 12967: 12960: 12953: 12946: 12926: 12919: 12912: 12905: 12898: 12786: 12776: 12769: 12762: 12755: 12748: 12741: 12724: 12717: 12710: 12703: 12696: 12689: 12571: 12564: 12557: 12550: 12543: 12536: 12524: 12517: 12510: 12503: 12496: 12489: 10231: 10210:disphenoid tetrahedral honeycomb 10195:tetrahedral-octahedral honeycomb 9531: 9528: 9525: 9514: 9448: 9440: 6989: 6945: 6901: 6832: 6824: 6792: 6784: 6752: 6744: 6698: 6694: 6686: 6678: 6671: 6663: 6654: 6646: 6637: 6633: 6625: 6617: 6608: 6600: 6593: 6585: 6576: 6572: 6457: 6400: 6343: 6299: 6290: 6281: 6225: 6218: 6211: 6136: 6128: 6120: 6112: 6104: 6096: 5999: 5938: 5877: 5816: 5585: 5579: 5509: 5503: 5463: 5458: 5453: 5448: 5443: 5402: 5357: 5352: 5347: 5342: 5337: 5312: 5262: 5186: 5113: 5068: 5063: 5058: 5053: 5048: 5011: 4865:tetrahedral-octahedral honeycomb 4857:disphenoid tetrahedral honeycomb 3383: 3378: 3373: 3368: 3363: 3355: 3350: 3345: 3340: 3335: 3305: 3300: 3295: 3290: 3285: 3277: 3272: 3267: 3262: 3257: 3049: 3040: 2951: 2944: 2845: 2838: 2494: 2489: 2484: 2479: 2474: 940:{\displaystyle r_{\mathrm {E} }} 908:{\displaystyle r_{\mathrm {M} }} 298:Regular tetrahedra alone do not 287:. The dual of this solid is the 196: 179: 167: 110:, and may thus also be called a 15949: 15920: 15886: 15864: 15842: 15806: 15770: 15740:Vondran, Gary L. (April 1998). 15733: 15701:"Resistance-Distance Sum Rules" 15692: 15667: 15605: 15562: 15527: 15509: 15482: 15409: 15369: 15350: 15332: 15298: 15289: 15235: 15184: 15111: 15016: 14990: 14955: 14026: 12421:Related polyhedra and compounds 11881:of a tetrahedron with vertices 11869: 11663: 10205: 10068:is the angle between the faces 9366:the volume of the tetrahedron. 9293: 9184: 9075: 8974: 8923: 8483:Six edge-lengths of Tetrahedron 4931: 3180: 2914:This property also applies for 2385: 2316: 2194: 2064: 1927: 1919: 1689:of the base, the distance from 1071: 984: 326: 117:The tetrahedron is one kind of 15820:Principles of physical geology 14926: 14848: 14768: 14626:Table of graphs and parameters 14327: 14153:Tetrahedral molecular geometry 14070:partial differential equations 11839: 11809: 11806: 11779: 11776: 11749: 11746: 11719: 11211: 11175: 10886: 10760: 10147:lies outside the tetrahedron. 10119:, measures exactly π sr, then 10103:to the vertices is a minimum, 10021: 10008: 9995: 9982: 9969: 9956: 9941: 9928: 9907: 9894: 9881: 9868: 9853: 9840: 9827: 9814: 9793: 9780: 9765: 9752: 9739: 9726: 9713: 9700: 9542: 9538: 9510: 9506: 9340: 9322: 9318: 9300: 9285: 9267: 9264: 9246: 9230: 9212: 9209: 9191: 9176: 9158: 9155: 9137: 9121: 9103: 9100: 9082: 9067: 9049: 9046: 9028: 8855: 8831: 8827: 8803: 8799: 8775: 8771: 8744: 6996: 6982: 6952: 6938: 6908: 6894: 6503: 6464: 6446: 6407: 6389: 6350: 6306: 6274: 6232: 6204: 6140: 6092: 6049: 6010: 5988: 5949: 5927: 5888: 5866: 5827: 5125:triangle base and three equal 4630:, a right triangle with edges 3140:, as at the corner of a cube. 3087:that join the vertices to the 2713:unit quaternion representation 2410: 2386: 2375: 2351: 2341: 2317: 2306: 2288: 2213: 2195: 1848:This is approximately 0.55129 1681:of a face. In other words, if 321: 13: 1: 16527:(two infinite groups and 75) 16306: 16214:Shavinina, Larisa V. (2013). 15641:Journal of Chemical Education 15418:Chemistry: A European Journal 15252:American Mathematical Monthly 14861:, Macmillan, pp. 294–295 14813: 14774:It is also the angle between 14227:), or approximately 109.47°. 10441:Trigonometry of a tetrahedron 10435:Law of cosines for tetrahedra 10240:Trigonometry of a tetrahedron 5694:{\displaystyle {\sqrt {3/2}}} 5469:and Schläfli symbol sr{2,2}. 5434:, present as the point group 3149: 3074:semi-orthocentric tetrahedron 2982:A single 30-tetrahedron ring 2875:A central cross section of a 17072:Degenerate polyhedra are in 16545:(two infinite groups and 50) 16194:"Regular polytope distances" 15714:(2): 633–649. Archived from 15545:ACM Transactions on Graphics 15045:10.1016/0898-1221(89)90148-X 14669: 14123: 14074:computational fluid dynamics 13971:five intersecting tetrahedra 12994: 12938: 12890: 12845: 10630:{\displaystyle \theta _{ij}} 7858:for the area of a triangle. 5655:Longest Edge Bisection (LEB) 5363:and Schläfli symbol s{2,4}. 5043:. A regular tetrahedron has 5025:It forms the symmetry group 4249: 4247: 4208: 4203: 4201: 4160: 4158: 4156: 4154: 4114: 4070: 4068: 4066: 4064: 4024: 3980: 3978: 3976: 3974: 3934: 3848: 3843: 3803: 3798: 3758: 3721: 3716: 3676: 3671: 3648: 3611: 3606: 3597:{\displaystyle 2{\text{𝜿}}} 3578: 3573: 3533: 3482: 3477: 3443: 3438: 3415: 3401: 3013:with tetrahedral cells (the 2942: 2852: 2833: 2670:{\displaystyle \mathrm {T} } 2450:{\displaystyle 2{\sqrt {2}}} 1662:) is twice that of an edge ( 205:a thin volume of empty space 155:to the tetrahedron's faces. 80:composed of four triangular 7: 16891:pentagonal icositetrahedron 16832:truncated icosidodecahedron 16025:Cromwell, Peter R. (1997). 15028:"Trisecting an Orthoscheme" 14998:"Sections of a Tetrahedron" 14683: 14487:who advised Kubrick on the 14367:, this solid is known as a 14279:Electricity and electronics 14111: 13949:Compound of five tetrahedra 13394:Duals to uniform polyhedra 12347: 11243:of its triangular faces as 11230: 11122:of the perpendiculars from 10914:for which the vertices are 10573:{\displaystyle \Delta _{i}} 10193:that can tile space as the 7207:, does so for the vertices 4192:{\displaystyle {\text{𝜿}}} 4176: 4074: 3984: 3894: 3755: 3645: 3530: 3412: 3399: 2998:aperiodic chain called the 2543: 10: 17733: 17659: 17086: 16921:pentagonal hexecontahedron 16881:deltoidal icositetrahedron 16168:10.4310/cag.2005.v13.n2.a5 16033:Cambridge University Press 16016:(3rd ed.). New York: 15699:Klein, Douglas J. (2002). 15470:Inequalities proposed in “ 15339:Audet, Daniel (May 2011). 14751:Trirectangular tetrahedron 14405:, originally published by 14394: 14390: 14331: 14282: 14150: 13999:compound of ten tetrahedra 13963:Compound of ten tetrahedra 13723: 13517: 12375: 12356:of its four vertices, see 10667:{\displaystyle P_{i}P_{j}} 10438: 10237: 10181:Regular tetrahedra cannot 7230:If we do not require that 3331:characteristic orthoscheme 3239:characteristic of the cube 3153: 3130:trirectangular tetrahedron 3116:Trirectangular tetrahedron 3113: 3110:Trirectangular tetrahedron 3091:of the opposite faces are 2465:, a polyhedron that is by 308:alternated cubic honeycomb 283:the tetrahedron becomes a 29: 27:Polyhedron with four faces 17070: 17004: 16979: 16961: 16954: 16929: 16916:disdyakis triacontahedron 16911:deltoidal hexecontahedron 16845: 16753: 16708: 16618: 16597:Kepler–Poinsot polyhedron 16589: 16554: 16502: 16443: 16382: 16321: 16314: 16117:(Thesis). pp. 16–17. 15908:(1432supp): s2294–22950. 15679:American Chemical Society 15137:10.1016/j.amc.2024.128631 14661:, each a skeleton of its 14624: 14590: 14580: 14570: 14560: 14550: 14540: 14530: 14520: 14511: 14506: 14371:, one of the more common 14258:communication engineering 13775: 13769: 13761: 13567: 13561: 13555: 13393: 13045: 13038: 12886:Apeirogonal trapezohedron 12483: 12480: 12434: 10244:A corollary of the usual 7472:Cayley–Menger determinant 5709: 5578: 5575: 5502: 5497: 5492: 5401: 5396: 5311: 5306: 5298: 5261: 5256: 5207:, also isomorphic to the 5185: 5182: 5112: 5109: 5010: 5007: 4978: 4973: 4966: 4963: 4948:3-dimensional point group 4871:cells in a ratio of 2:1. 4838:space-filling tetrahedron 3394: 3227:birectangular tetrahedron 3132:the three face angles at 2964: 2617:. This symmetry group is 2585:full tetrahedral symmetry 2004:plane, the vertices are: 16052:The Mathematical Gazette 15850:Hitchcock, Charles Henry 15230:Murakami & Yano 2005 15159:Alsina & Nelsen 2015 14946:Alsina & Nelsen 2015 14858:Plane and Solid Geometry 14761: 14721:– 4-dimensional analogue 14469:originally intended the 14341: 13935:Two tetrahedra in a cube 12873:Pentagonal trapezohedron 12868:Tetragonal trapezohedron 12363: 9589:orthocentric tetrahedron 9373:or in three-dimensional 4832:Space-filling tetrahedra 3070:orthocentric tetrahedron 2966:Stereographic projection 2932:stereographic projection 2552:The cube and tetrahedron 2230:with the edge length of 30:Not to be confused with 17022:gyroelongated bipyramid 16896:rhombic triacontahedron 16802:truncated cuboctahedron 16609:Uniform star polyhedron 16537:quasiregular polyhedron 16192:Park, Poo-Sung (2016). 15982:Elemente der Mathematik 15778:Green, William Lowthian 15557:10.1145/1778765.1778856 14485:artificial intelligence 14314:solid-state electronics 14062:finite element analysis 13923:Compounds of tetrahedra 13508:}, continuing into the 12878:Hexagonal trapezohedron 12738:Spherical tiling image 7818:represent the vertices 5302:(Four equal triangles) 4861:Hilbert's third problem 4105:{\displaystyle _{2}R/l} 4015:{\displaystyle _{1}R/l} 3925:{\displaystyle _{0}R/l} 3068:, then it is called an 2961:Orthographic projection 2818:Orthographic projection 99:The tetrahedron is the 17017:truncated trapezohedra 16886:disdyakis dodecahedron 16852:(duals of Archimedean) 16827:rhombicosidodecahedron 16817:truncated dodecahedron 16543:semiregular polyhedron 16087:Fekete, A. E. (1985). 15894:Bell, Alexander Graham 15858:The American Geologist 15583:(5): 162–166, May 1985 15516:Todhunter, I. (1886), 15489:Crelle, A. L. (1821). 15430:10.1002/chem.200400869 15032:Computers Math. Applic 14780:tetrahedral bond angle 14715:-dimensional analogues 14690:Boerdijk–Coxeter helix 14407:William Lowthian Green 14403:tetrahedral hypothesis 14397:tetrahedral hypothesis 14353: 14148: 14137: 14100:Structural engineering 14096:, and related fields. 14082:electromagnetic fields 14041: 13776:Noncompact hyperbolic 13568:Noncompact hyperbolic 12863:Trigonal trapezohedron 12404:, while the volume is 12335: 11860: 11654: 11525: 11390: 11256:= 1, 2, 3, 4, we have 11221: 11077: 10893: 10668: 10631: 10601: 10574: 10547: 10520: 10493: 10466: 10405: 10176:compound of five cubes 10052: 9614:at a point called the 9559: 9480: 9456: 9426: 9406: 9354: 9005: 8882: 8721: 8701: 8681: 8661: 8641: 8621: 8601: 8581: 8561: 8541: 8521: 8501: 8484: 8471: 8321: 8141: 7995: 7975: 7955: 7935: 7915: 7895: 7875: 7798: 7461: 7162: 7005: 6961: 6917: 6870: 6716: 6520: 6315: 6241: 6147: 6063: 5794: 5770: 5750: 5695: 5270:Four unequal triangles 4912:Coxeter-Dynkin diagram 4884: 4821: 4788: 4755: 4722: 4689: 4656: 4623: 4590: 4557: 4531: 4498: 4465: 4439: 4406: 4373: 4336: 4303: 4281: 4239: 4193: 4146: 4106: 4056: 4016: 3966: 3926: 3872: 3835: 3790: 3745: 3708: 3663: 3635: 3598: 3565: 3508: 3469: 3430: 3229:. It is also called a 3190: 3169: 3125: 3081:isodynamic tetrahedron 3000:Boerdijk–Coxeter helix 2991: 2984:Boerdijk–Coxeter helix 2916:tetragonal disphenoids 2911: 2884: 2804:orthogonal projections 2718:identity (identity; 1) 2701: 2671: 2645: 2611: 2576: 2553: 2534: 2469:a cube. This form has 2451: 2424: 2260: 2224: 1998: 1969: 1842: 1643: 1177: 1150: 1130: 1110: 941: 909: 877: 854: 834: 821: 636: 502: 470: 370: 350: 333: 16906:pentakis dodecahedron 16822:truncated icosahedron 16777:truncated tetrahedron 16590:non-convex polyhedron 16108:Kahan, W. M. (2012). 16093:. Marcel Dekker Inc. 15708:Croatica Chemica Acta 15599:Pythagorean Triangles 14800:characteristic angles 14476:2001: A Space Odyssey 14349: 14143: 14131: 14039: 12853:Digonal trapezohedron 12680:Apeirogonal antiprism 12336: 11861: 11655: 11526: 11391: 11222: 11078: 10894: 10669: 10632: 10602: 10600:{\displaystyle P_{i}} 10575: 10548: 10546:{\displaystyle P_{4}} 10521: 10519:{\displaystyle P_{3}} 10494: 10492:{\displaystyle P_{2}} 10467: 10465:{\displaystyle P_{1}} 10406: 10155:A tetrahedron is a 3- 10139:still corresponds to 10053: 9560: 9481: 9457: 9427: 9407: 9383:Murakami–Yano formula 9355: 9006: 8883: 8722: 8702: 8682: 8662: 8642: 8622: 8602: 8582: 8562: 8542: 8522: 8502: 8482: 8472: 8322: 8142: 7996: 7976: 7956: 7936: 7916: 7896: 7876: 7852:Piero della Francesca 7807:where the subscripts 7799: 7462: 7163: 7006: 6962: 6918: 6871: 6717: 6521: 6316: 6242: 6148: 6064: 5795: 5771: 5751: 5696: 5308:Tetragonal disphenoid 5257:Irregular tetrahedron 4882: 4822: 4789: 4756: 4723: 4690: 4657: 4624: 4591: 4558: 4532: 4499: 4466: 4440: 4407: 4374: 4345:characteristic angles 4337: 4304: 4282: 4240: 4194: 4147: 4107: 4057: 4017: 3967: 3927: 3873: 3836: 3791: 3746: 3709: 3664: 3636: 3599: 3566: 3509: 3470: 3431: 3188: 3163: 3123: 2981: 2934:. This projection is 2909: 2874: 2702: 2700:{\displaystyle A_{4}} 2672: 2646: 2644:{\displaystyle S_{4}} 2612: 2574: 2551: 2535: 2452: 2425: 2275:Cartesian coordinates 2261: 2225: 1999: 1970: 1870:Cartesian coordinates 1864:Cartesian coordinates 1843: 1644: 1178: 1176:{\displaystyle d_{i}} 1151: 1131: 1111: 942: 910: 878: 855: 832: 822: 637: 503: 471: 371: 351: 331: 285:truncated tetrahedron 268:. Its interior is an 220:equilateral triangles 17707:Prismatoid polyhedra 16866:rhombic dodecahedron 16792:truncated octahedron 15382:Mathematics Magazine 14745:Triangular dipyramid 14725:Synergetics (Fuller) 14695:Möbius configuration 14316:, and silicon has a 14267:allotrope and tetra- 14090:chemical engineering 12842:-gonal trapezohedra 12672:Heptagonal antiprism 12662:Pentagonal antiprism 12650:Triangular antiprism 12378:Heronian tetrahedron 11924: 11707: 11540: 11449: 11263: 11133: 10965: 10682: 10641: 10611: 10584: 10557: 10530: 10503: 10476: 10449: 10271: 9674: 9620:Commandino's theorem 9490: 9470: 9436: 9416: 9396: 9015: 8892: 8731: 8711: 8691: 8671: 8651: 8631: 8611: 8591: 8571: 8551: 8531: 8511: 8491: 8331: 8151: 8005: 7985: 7965: 7945: 7925: 7905: 7885: 7865: 7481: 7241: 7018: 6971: 6927: 6883: 6732: 6540: 6331: 6257: 6187: 6076: 5808: 5784: 5760: 5718: 5673: 5531:, isomorphic to the 5139:, isomorphic to the 5032:, isomorphic to the 5008:Regular tetrahedron 4800: 4767: 4734: 4701: 4668: 4635: 4602: 4569: 4547: 4510: 4477: 4455: 4448:characteristic radii 4446:(edges that are the 4418: 4385: 4352: 4315: 4293: 4260: 4213: 4181: 4119: 4079: 4029: 3989: 3939: 3899: 3853: 3808: 3763: 3726: 3681: 3653: 3616: 3583: 3538: 3487: 3448: 3420: 3324:Heronian tetrahedron 3106:of the tetrahedron. 3100:isogonic tetrahedron 3083:is one in which the 3033:Irregular tetrahedra 2684: 2659: 2628: 2590: 2507: 2434: 2281: 2277:of the vertices are 2234: 2008: 1985: 1876: 1713: 1187: 1160: 1140: 1120: 951: 922: 890: 867: 844: 653: 512: 480: 380: 360: 340: 312:Schläfli orthoscheme 262:stellated octahedron 17712:Pyramids (geometry) 17702:Self-dual polyhedra 17654:pentagonal polytope 17553:Uniform 10-polytope 17113:Fundamental convex 16901:triakis icosahedron 16876:tetrakis hexahedron 16861:triakis tetrahedron 16797:rhombicuboctahedron 16202:Forum Geometricorum 16090:Real Linear Algebra 15932:"Tetrahedral graph" 15902:Scientific American 15792:1875vmge.book.....G 15749:HP Technical Report 15653:1945JChEd..22..145B 15577:Crux Mathematicorum 15551:(4): 119:1–119:11, 15472:Crux Mathematicorum 14740:Tetrahedron packing 14611:distance-transitive 14460:Tetrahedral objects 14308:is the most common 14167:lone electron pairs 14017:Szilassi polyhedron 12843: 12783:Plane tiling image 12667:Hexagonal antiprism 12635: 12388:isosceles triangles 12384:Heronian tetrahedra 11360: 11335: 11310: 11285: 10753: 10735: 10717: 10699: 10151:Geometric relations 10107:coincides with the 9639:twelve-point sphere 7848:Tartaglia's formula 7780: 7763: 7746: 7722: 7700: 7683: 7659: 7642: 7620: 7596: 7579: 7562: 5593:Two pairs of equal 5576:Phyllic disphenoid 5517:Two pairs of equal 5110:Triangular pyramid 4897:Goursat tetrahedron 4895:is an example of a 4875:Fundamental domains 3011:regular 4-polytopes 2889:regular tetrahedron 2877:regular tetrahedron 2820: 1620: 1602: 1584: 1566: 1520: 1502: 1484: 1466: 1381: 1363: 1345: 1327: 1265: 1247: 1229: 1211: 289:triakis tetrahedron 276:the tetrahedron). 216:regular tetrahedron 159:Regular tetrahedron 72:), also known as a 17523:Uniform 9-polytope 17473:Uniform 8-polytope 17423:Uniform 7-polytope 17380:Uniform 6-polytope 17350:Uniform 5-polytope 17310:Uniform polychoron 17273:Uniform polyhedron 17121:in dimensions 2–10 16871:triakis octahedron 16756:Archimedean solids 16531:regular polyhedron 16525:uniform polyhedron 16487:Hectotriadiohedron 16243:Weisstein, Eric W. 16018:Dover Publications 15929:Weisstein, Eric W. 15824:. Nelson. p.  15675:"White phosphorus" 15377:Senechal, Marjorie 15365:(Part 1): 189–203. 15106:fundamental region 14832:Weisstein, Eric W. 14735:Tetrahedral number 14615:3-vertex-connected 14354: 14149: 14138: 14136:ion is tetrahedral 14066:numerical solution 14064:especially in the 14046:numerical analysis 14042: 14032:Numerical analysis 14021:Császár polyhedron 14003:stellae octangulae 12997:Face configuration 12837: 12598: 12372:Integer tetrahedra 12331: 12329: 12321: 12115: 11856: 11650: 11521: 11386: 11346: 11321: 11296: 11271: 11217: 11073: 10889: 10739: 10721: 10703: 10685: 10664: 10627: 10597: 10570: 10543: 10516: 10489: 10462: 10428:degrees of freedom 10401: 10048: 10035: 9555: 9476: 9452: 9422: 9402: 9369:For tetrahedra in 9350: 9348: 9001: 8999: 8878: 8717: 8697: 8677: 8657: 8637: 8617: 8597: 8577: 8557: 8537: 8517: 8497: 8485: 8467: 8317: 8315: 8137: 7991: 7971: 7951: 7931: 7911: 7891: 7871: 7794: 7788: 7766: 7749: 7732: 7708: 7686: 7669: 7645: 7628: 7606: 7582: 7565: 7548: 7457: 7442: 7158: 7001: 6995: 6957: 6951: 6913: 6907: 6866: 6861: 6712: 6706: 6516: 6511: 6311: 6305: 6237: 6231: 6143: 6059: 6057: 5790: 5766: 5746: 5705:General properties 5691: 5611:isomorphic to the 5499:Digonal disphenoid 5398:Rhombic disphenoid 5183:Mirrored sphenoid 4889:fundamental domain 4885: 4850:scissors-congruent 4817: 4814: 4784: 4781: 4751: 4748: 4718: 4715: 4685: 4682: 4652: 4649: 4619: 4616: 4586: 4583: 4553: 4527: 4524: 4494: 4491: 4461: 4435: 4432: 4402: 4399: 4369: 4366: 4347:𝟀, 𝝉, 𝟁), plus 4332: 4329: 4299: 4277: 4274: 4235: 4233: 4189: 4142: 4133: 4102: 4052: 4043: 4012: 3962: 3953: 3922: 3868: 3866: 3831: 3821: 3786: 3777: 3741: 3739: 3704: 3694: 3659: 3631: 3629: 3594: 3561: 3552: 3504: 3465: 3426: 3248:and one of length 3191: 3170: 3126: 2992: 2912: 2885: 2816: 2697: 2667: 2641: 2607: 2577: 2556:The vertices of a 2554: 2530: 2447: 2420: 2418: 2256: 2220: 2218: 1997:{\displaystyle xy} 1994: 1965: 1925: 1838: 1836: 1639: 1637: 1606: 1588: 1570: 1552: 1506: 1488: 1470: 1452: 1367: 1349: 1331: 1313: 1251: 1233: 1215: 1197: 1173: 1146: 1126: 1106: 1104: 937: 905: 873: 850: 835: 817: 815: 632: 498: 466: 366: 346: 334: 318:, can tessellate. 74:triangular pyramid 17697:Individual graphs 17675: 17674: 17662:Polytope families 17119:uniform polytopes 17081: 17080: 17000: 16999: 16837:snub dodecahedron 16812:icosidodecahedron 16667: 16666: 16568:Archimedean solid 16555:convex polyhedron 16463:Icosidodecahedron 16225:978-0-203-38714-6 16100:978-0-8247-7238-3 16042:978-0-521-55432-9 16013:Regular Polytopes 16002:. Methuen and Co. 15999:Regular Polytopes 15994:Coxeter, H. S. M. 15972:978-1-61444-216-5 15661:10.1021/ed022p145 15594:Wacław Sierpiński 15424:(24): 6575–6580. 14681: 14680: 14657:. It is one of 5 14631: 14630: 14507:Tetrahedral graph 14500:Tetrahedral graph 14159:covalently bonded 14086:civil engineering 14010:square hosohedron 13993:forms, which are 13985:. There are both 13920: 13919: 13712: 13711: 13498: 13497: 13027:uniform polyhedra 13023: 13022: 12825: 12824: 12686:Polyhedron image 12643:Digonal antiprism 12582: 12581: 12154: 12137: 12131: 12125: 11968: 11962: 11851: 11842: 11635: 11609: 11583: 11557: 11519: 11381: 11361: 11336: 11311: 11286: 11102:, interior point 10221:uniform polyhedra 9635:nine-point circle 9550: 9479:{\displaystyle V} 9425:{\displaystyle a} 9405:{\displaystyle d} 9375:elliptic geometry 8992: 8967: 8941: 8916: 8876: 8858: 8720:{\displaystyle W} 8700:{\displaystyle w} 8680:{\displaystyle V} 8660:{\displaystyle v} 8640:{\displaystyle U} 8620:{\displaystyle u} 8600:{\displaystyle w} 8580:{\displaystyle v} 8560:{\displaystyle u} 8540:{\displaystyle W} 8520:{\displaystyle V} 8500:{\displaystyle U} 8465: 8356: 8135: 8131: 7994:{\displaystyle V} 7974:{\displaystyle z} 7954:{\displaystyle y} 7934:{\displaystyle x} 7914:{\displaystyle c} 7894:{\displaystyle b} 7874:{\displaystyle a} 7152: 7043: 6087: 5793:{\displaystyle h} 5769:{\displaystyle A} 5735: 5689: 5645: 5644: 4964:Tetrahedron name 4827: 4815: 4813: 4794: 4782: 4780: 4761: 4749: 4747: 4728: 4716: 4714: 4695: 4683: 4681: 4662: 4650: 4648: 4629: 4617: 4615: 4596: 4584: 4582: 4563: 4556:{\displaystyle 1} 4540:60-90-30 triangle 4537: 4525: 4523: 4504: 4492: 4490: 4471: 4464:{\displaystyle 1} 4445: 4433: 4431: 4412: 4400: 4398: 4379: 4367: 4365: 4342: 4330: 4328: 4309: 4302:{\displaystyle 1} 4287: 4275: 4273: 4253: 4252: 4245: 4232: 4223: 4206: 4199: 4187: 4152: 4134: 4132: 4112: 4062: 4044: 4042: 4022: 3972: 3954: 3952: 3932: 3878: 3865: 3846: 3841: 3829: 3820: 3801: 3796: 3778: 3776: 3751: 3738: 3719: 3714: 3702: 3693: 3674: 3669: 3662:{\displaystyle 1} 3641: 3628: 3609: 3604: 3592: 3576: 3571: 3553: 3551: 3514: 3502: 3480: 3475: 3463: 3441: 3436: 3429:{\displaystyle 2} 3231:quadrirectangular 3059: 3058: 3009:, all the convex 2971: 2970: 2864: 2863: 2709:conjugacy classes 2679:alternating group 2445: 2254: 2248: 2180: 2164: 2163: 2146: 2145: 2114: 2098: 2097: 2083: 2082: 2052: 2030: 2029: 1958: 1957: 1924: 1912: 1911: 1822: 1785: 1759: 1738: 1411: 1386: 1295: 1270: 1149:{\displaystyle R} 1129:{\displaystyle a} 1097: 1096: 1064: 1063: 1049: 1017: 1016: 999: 974: 970: 876:{\displaystyle r} 853:{\displaystyle R} 837:The radii of its 791: 759: 710: 678: 611: 608: 579: 575: 549: 545: 529: 493: 489: 445: 410: 406: 369:{\displaystyle A} 349:{\displaystyle a} 304:regular octahedra 101:three-dimensional 18:Tetrahedral angle 16:(Redirected from 17724: 17666:Regular polytope 17227: 17216: 17205: 17164: 17107: 17100: 17093: 17084: 17083: 16959: 16958: 16955:Dihedral uniform 16930:Dihedral regular 16853: 16769: 16718: 16694: 16687: 16680: 16671: 16670: 16503:elemental things 16481:Enneacontahedron 16451:Icositetrahedron 16301: 16294: 16287: 16278: 16277: 16256: 16255: 16229: 16210: 16198: 16188: 16170: 16145: 16132: 16131:. Johann Planck. 16123:Kepler, Johannes 16118: 16116: 16104: 16083: 16058:(318): 263–266. 16046: 16021: 16003: 15989: 15976: 15943: 15942: 15941: 15924: 15918: 15917: 15890: 15884: 15883: 15881: 15879: 15874:. Web of Stories 15868: 15862: 15861: 15846: 15840: 15839: 15823: 15810: 15804: 15803: 15774: 15768: 15767: 15765: 15763: 15757: 15746: 15737: 15731: 15730: 15728: 15726: 15720: 15705: 15696: 15690: 15689: 15687: 15685: 15671: 15665: 15664: 15636: 15630: 15628: 15609: 15603: 15591: 15585: 15584: 15574: 15566: 15560: 15559: 15542: 15531: 15525: 15523: 15513: 15507: 15506: 15504: 15502: 15486: 15480: 15467: 15454: 15448: 15442: 15441: 15413: 15407: 15406: 15373: 15367: 15366: 15354: 15348: 15347: 15345: 15336: 15330: 15329: 15323: 15315: 15313: 15302: 15296: 15293: 15287: 15286: 15268: 15248: 15239: 15233: 15227: 15221: 15215: 15209: 15203: 15194: 15188: 15182: 15172: 15166: 15156: 15150: 15149: 15139: 15115: 15109: 15099: 15093: 15087: 15081: 15071: 15065: 15059: 15050: 15049: 15047: 15020: 15014: 15008: 15002: 15001: 14994: 14988: 14982: 14976: 14959: 14953: 14943: 14937: 14932:Köller, Jürgen, 14930: 14924: 14918: 14907: 14897: 14891: 14881: 14875: 14869: 14863: 14862: 14852: 14846: 14845: 14844: 14827: 14807: 14792: 14783: 14772: 14730:Tetrahedral kite 14677:3-fold symmetry 14675: 14668: 14667: 14607:distance-regular 14582:Chromatic number 14516: 14504: 14503: 14454: 14445: 14434: 14425: 14358:Royal Game of Ur 14265:white phosphorus 14245: 14243: 14242: 14226: 14224: 14223: 14220: 14217: 14200: 14199: 14198: 14184: 14183: 14182: 13959: 13945: 13931: 13862: 13855: 13848: 13841: 13834: 13827: 13820: 13813: 13806: 13799: 13792: 13785: 13770:Compact hyperb. 13753: 13746: 13739: 13721: 13720: 13654: 13647: 13640: 13633: 13626: 13619: 13612: 13605: 13598: 13591: 13584: 13577: 13547: 13540: 13533: 13515: 13514: 13510:hyperbolic plane 13502:Schläfli symbols 13452: 13445: 13438: 13431: 13424: 13417: 13410: 13403: 13347: 13346: 13345: 13341: 13340: 13336: 13335: 13331: 13330: 13326: 13325: 13318: 13317: 13316: 13312: 13311: 13307: 13306: 13302: 13301: 13297: 13296: 13289: 13288: 13287: 13283: 13282: 13278: 13277: 13273: 13272: 13268: 13267: 13260: 13259: 13258: 13254: 13253: 13249: 13248: 13244: 13243: 13239: 13238: 13231: 13230: 13229: 13225: 13224: 13220: 13219: 13215: 13214: 13210: 13209: 13202: 13201: 13200: 13196: 13195: 13191: 13190: 13186: 13185: 13181: 13180: 13173: 13172: 13171: 13167: 13166: 13162: 13161: 13157: 13156: 13152: 13151: 13144: 13143: 13142: 13138: 13137: 13133: 13132: 13128: 13127: 13123: 13122: 13113: 13106: 13099: 13092: 13085: 13078: 13071: 13064: 13036: 13035: 12991: 12978: 12971: 12964: 12957: 12950: 12941:Spherical tiling 12930: 12923: 12916: 12909: 12902: 12844: 12836: 12790: 12780: 12773: 12766: 12759: 12752: 12745: 12728: 12721: 12714: 12707: 12700: 12693: 12657:Square antiprism 12636: 12630: 12623: 12616: 12597: 12575: 12568: 12561: 12554: 12547: 12540: 12528: 12521: 12514: 12507: 12500: 12493: 12436:Regular pyramids 12432: 12431: 12413: 12412: 12409: 12403: 12402: 12396: 12395: 12340: 12338: 12337: 12332: 12330: 12326: 12322: 12318: 12317: 12308: 12307: 12292: 12291: 12282: 12281: 12265: 12264: 12255: 12254: 12239: 12238: 12229: 12228: 12212: 12211: 12202: 12201: 12186: 12185: 12176: 12175: 12155: 12147: 12135: 12132: 12129: 12123: 12120: 12116: 12112: 12111: 12106: 12102: 12101: 12100: 12088: 12087: 12068: 12067: 12062: 12058: 12057: 12056: 12044: 12043: 12024: 12023: 12018: 12014: 12013: 12012: 12000: 11999: 11966: 11963: 11960: 11953: 11952: 11916: 11907: 11898: 11889: 11880: 11865: 11863: 11862: 11857: 11852: 11850: 11718: 11717: 11659: 11657: 11656: 11651: 11646: 11645: 11636: 11628: 11620: 11619: 11610: 11602: 11594: 11593: 11584: 11576: 11568: 11567: 11558: 11550: 11530: 11528: 11527: 11522: 11520: 11518: 11517: 11516: 11504: 11503: 11491: 11490: 11478: 11477: 11467: 11459: 11395: 11393: 11392: 11387: 11382: 11380: 11379: 11367: 11362: 11359: 11354: 11342: 11337: 11334: 11329: 11317: 11312: 11309: 11304: 11292: 11287: 11284: 11279: 11267: 11226: 11224: 11223: 11218: 11082: 11080: 11079: 11074: 11060: 11059: 11058: 11036: 11035: 11034: 11012: 11011: 11010: 10988: 10987: 10986: 10898: 10896: 10895: 10890: 10885: 10884: 10866: 10865: 10856: 10855: 10843: 10842: 10824: 10823: 10814: 10813: 10801: 10800: 10782: 10781: 10772: 10771: 10752: 10747: 10734: 10729: 10716: 10711: 10698: 10693: 10673: 10671: 10670: 10665: 10663: 10662: 10653: 10652: 10636: 10634: 10633: 10628: 10626: 10625: 10606: 10604: 10603: 10598: 10596: 10595: 10579: 10577: 10576: 10571: 10569: 10568: 10552: 10550: 10549: 10544: 10542: 10541: 10525: 10523: 10522: 10517: 10515: 10514: 10498: 10496: 10495: 10490: 10488: 10487: 10471: 10469: 10468: 10463: 10461: 10460: 10410: 10408: 10407: 10402: 10235: 10183:tessellate space 10161:electromagnetism 10109:geometric median 10081:geometric median 10057: 10055: 10054: 10049: 10040: 10039: 10024: 10020: 10019: 9998: 9994: 9993: 9972: 9968: 9967: 9944: 9940: 9939: 9910: 9906: 9905: 9884: 9880: 9879: 9856: 9852: 9851: 9830: 9826: 9825: 9796: 9792: 9791: 9768: 9764: 9763: 9742: 9738: 9737: 9716: 9712: 9711: 9564: 9562: 9561: 9556: 9551: 9546: 9545: 9537: 9517: 9509: 9500: 9485: 9483: 9482: 9477: 9461: 9459: 9458: 9453: 9451: 9443: 9431: 9429: 9428: 9423: 9411: 9409: 9408: 9403: 9371:hyperbolic space 9359: 9357: 9356: 9351: 9349: 9010: 9008: 9007: 9002: 9000: 8993: 8982: 8968: 8957: 8942: 8931: 8917: 8906: 8887: 8885: 8884: 8879: 8877: 8875: 8742: 8741: 8726: 8724: 8723: 8718: 8706: 8704: 8703: 8698: 8686: 8684: 8683: 8678: 8666: 8664: 8663: 8658: 8646: 8644: 8643: 8638: 8626: 8624: 8623: 8618: 8606: 8604: 8603: 8598: 8586: 8584: 8583: 8578: 8566: 8564: 8563: 8558: 8546: 8544: 8543: 8538: 8526: 8524: 8523: 8518: 8506: 8504: 8503: 8498: 8476: 8474: 8473: 8468: 8466: 8464: 8456: 8455: 8443: 8435: 8434: 8422: 8414: 8413: 8401: 8390: 8379: 8359: 8357: 8352: 8341: 8326: 8324: 8323: 8318: 8316: 8309: 8308: 8296: 8295: 8283: 8282: 8256: 8255: 8243: 8242: 8230: 8229: 8203: 8202: 8190: 8189: 8177: 8176: 8146: 8144: 8143: 8138: 8136: 8118: 8117: 8108: 8107: 8095: 8094: 8085: 8084: 8072: 8071: 8062: 8061: 8049: 8048: 8039: 8038: 8029: 8028: 8016: 8015: 8000: 7998: 7997: 7992: 7980: 7978: 7977: 7972: 7960: 7958: 7957: 7952: 7940: 7938: 7937: 7932: 7920: 7918: 7917: 7912: 7900: 7898: 7897: 7892: 7880: 7878: 7877: 7872: 7837: 7817: 7803: 7801: 7800: 7795: 7793: 7792: 7779: 7774: 7762: 7757: 7745: 7740: 7721: 7716: 7699: 7694: 7682: 7677: 7658: 7653: 7641: 7636: 7619: 7614: 7595: 7590: 7578: 7573: 7561: 7556: 7499: 7498: 7466: 7464: 7463: 7458: 7452: 7448: 7447: 7443: 7417: 7416: 7405: 7404: 7393: 7392: 7381: 7380: 7367: 7366: 7355: 7354: 7343: 7342: 7331: 7330: 7317: 7316: 7305: 7304: 7293: 7292: 7281: 7280: 7195:to the vertices 7167: 7165: 7164: 7159: 7153: 7151: 7143: 7142: 7130: 7122: 7121: 7109: 7101: 7100: 7088: 7077: 7066: 7046: 7044: 7039: 7028: 7010: 7008: 7007: 7002: 7000: 6999: 6992: 6966: 6964: 6963: 6958: 6956: 6955: 6948: 6922: 6920: 6919: 6914: 6912: 6911: 6904: 6875: 6873: 6872: 6867: 6865: 6864: 6855: 6835: 6827: 6815: 6795: 6787: 6775: 6755: 6747: 6728: 6724: 6721: 6719: 6718: 6713: 6711: 6710: 6703: 6702: 6701: 6689: 6681: 6674: 6666: 6657: 6649: 6642: 6641: 6640: 6628: 6620: 6611: 6603: 6596: 6588: 6581: 6580: 6579: 6558: 6557: 6528: 6525: 6523: 6522: 6517: 6515: 6514: 6502: 6501: 6489: 6488: 6476: 6475: 6460: 6445: 6444: 6432: 6431: 6419: 6418: 6403: 6388: 6387: 6375: 6374: 6362: 6361: 6346: 6327: 6323: 6320: 6318: 6317: 6312: 6310: 6309: 6302: 6293: 6284: 6253: 6249: 6246: 6244: 6243: 6238: 6236: 6235: 6228: 6221: 6214: 6176: 6174: 6173: 6170: 6167: 6152: 6150: 6149: 6144: 6139: 6131: 6123: 6115: 6107: 6099: 6088: 6080: 6068: 6066: 6065: 6060: 6058: 6048: 6047: 6035: 6034: 6022: 6021: 6002: 5987: 5986: 5974: 5973: 5961: 5960: 5941: 5926: 5925: 5913: 5912: 5900: 5899: 5880: 5865: 5864: 5852: 5851: 5839: 5838: 5819: 5799: 5797: 5796: 5791: 5775: 5773: 5772: 5767: 5755: 5753: 5752: 5747: 5736: 5728: 5700: 5698: 5697: 5692: 5690: 5685: 5677: 5662:similarity class 5589: 5583: 5533:Klein four-group 5513: 5507: 5468: 5467: 5466: 5462: 5461: 5457: 5456: 5452: 5451: 5447: 5446: 5419:Klein four-group 5406: 5362: 5361: 5360: 5356: 5355: 5351: 5350: 5346: 5345: 5341: 5340: 5316: 5266: 5190: 5117: 5073: 5072: 5071: 5067: 5066: 5062: 5061: 5057: 5056: 5052: 5051: 5015: 4961: 4960: 4920:generating point 4826: 4824: 4823: 4818: 4816: 4806: 4804: 4796: 4793: 4791: 4790: 4785: 4783: 4773: 4771: 4763: 4760: 4758: 4757: 4752: 4750: 4740: 4738: 4730: 4727: 4725: 4724: 4719: 4717: 4707: 4705: 4697: 4694: 4692: 4691: 4686: 4684: 4674: 4672: 4664: 4661: 4659: 4658: 4653: 4651: 4641: 4639: 4631: 4628: 4626: 4625: 4620: 4618: 4608: 4606: 4598: 4595: 4593: 4592: 4587: 4585: 4575: 4573: 4565: 4562: 4560: 4559: 4554: 4543: 4536: 4534: 4533: 4528: 4526: 4516: 4514: 4506: 4503: 4501: 4500: 4495: 4493: 4483: 4481: 4473: 4470: 4468: 4467: 4462: 4451: 4444: 4442: 4441: 4436: 4434: 4424: 4422: 4414: 4411: 4409: 4408: 4403: 4401: 4391: 4389: 4381: 4378: 4376: 4375: 4370: 4368: 4358: 4356: 4348: 4341: 4339: 4338: 4333: 4331: 4321: 4319: 4311: 4308: 4306: 4305: 4300: 4289: 4286: 4284: 4283: 4278: 4276: 4266: 4264: 4256: 4244: 4242: 4241: 4236: 4234: 4228: 4224: 4221: 4218: 4209: 4204: 4198: 4196: 4195: 4190: 4188: 4185: 4177: 4151: 4149: 4148: 4143: 4135: 4125: 4123: 4115: 4111: 4109: 4108: 4103: 4098: 4090: 4089: 4075: 4061: 4059: 4058: 4053: 4045: 4035: 4033: 4025: 4021: 4019: 4018: 4013: 4008: 4000: 3999: 3985: 3971: 3969: 3968: 3963: 3955: 3945: 3943: 3935: 3931: 3929: 3928: 3923: 3918: 3910: 3909: 3895: 3877: 3875: 3874: 3869: 3867: 3858: 3849: 3844: 3840: 3838: 3837: 3832: 3830: 3827: 3822: 3813: 3804: 3799: 3795: 3793: 3792: 3787: 3779: 3769: 3767: 3759: 3750: 3748: 3747: 3742: 3740: 3731: 3722: 3717: 3713: 3711: 3710: 3705: 3703: 3700: 3695: 3686: 3677: 3672: 3668: 3666: 3665: 3660: 3649: 3640: 3638: 3637: 3632: 3630: 3621: 3612: 3607: 3603: 3601: 3600: 3595: 3593: 3590: 3579: 3574: 3570: 3568: 3567: 3562: 3554: 3544: 3542: 3534: 3513: 3511: 3510: 3505: 3503: 3500: 3483: 3478: 3474: 3472: 3471: 3466: 3464: 3461: 3444: 3439: 3435: 3433: 3432: 3427: 3416: 3392: 3391: 3388: 3387: 3386: 3382: 3381: 3377: 3376: 3372: 3371: 3367: 3366: 3360: 3359: 3358: 3354: 3353: 3349: 3348: 3344: 3343: 3339: 3338: 3317: 3316: 3310: 3309: 3308: 3304: 3303: 3299: 3298: 3294: 3293: 3289: 3288: 3282: 3281: 3280: 3276: 3275: 3271: 3270: 3266: 3265: 3261: 3260: 3254: 3253: 3247: 3246: 3212:is an irregular 3104:inscribed sphere 3053: 3044: 3037: 2974:Helical stacking 2955: 2948: 2941: 2940: 2928:spherical tiling 2922:Spherical tiling 2849: 2842: 2821: 2815: 2802:has two special 2772: 2758: 2751: 2749: 2748: 2745: 2742: 2724: 2706: 2704: 2703: 2698: 2696: 2695: 2676: 2674: 2673: 2668: 2666: 2650: 2648: 2647: 2642: 2640: 2639: 2616: 2614: 2613: 2608: 2606: 2605: 2604: 2598: 2539: 2537: 2536: 2531: 2514: 2499: 2498: 2497: 2493: 2492: 2488: 2487: 2483: 2482: 2478: 2477: 2456: 2454: 2453: 2448: 2446: 2441: 2429: 2427: 2426: 2421: 2419: 2265: 2263: 2262: 2257: 2255: 2250: 2249: 2244: 2238: 2229: 2227: 2226: 2221: 2219: 2186: 2182: 2181: 2173: 2165: 2156: 2155: 2147: 2138: 2137: 2120: 2116: 2115: 2107: 2099: 2090: 2089: 2084: 2075: 2074: 2058: 2054: 2053: 2045: 2031: 2022: 2021: 2003: 2001: 2000: 1995: 1974: 1972: 1971: 1966: 1964: 1960: 1959: 1953: 1949: 1926: 1922: 1918: 1914: 1913: 1907: 1903: 1847: 1845: 1844: 1839: 1837: 1827: 1823: 1815: 1794: 1790: 1786: 1778: 1760: 1752: 1743: 1739: 1731: 1668: 1667: 1661: 1660: 1648: 1646: 1645: 1640: 1638: 1631: 1630: 1625: 1621: 1619: 1614: 1601: 1596: 1583: 1578: 1565: 1560: 1548: 1547: 1525: 1521: 1519: 1514: 1501: 1496: 1483: 1478: 1465: 1460: 1448: 1447: 1423: 1422: 1417: 1413: 1412: 1407: 1406: 1405: 1392: 1387: 1382: 1380: 1375: 1362: 1357: 1344: 1339: 1326: 1321: 1311: 1296: 1291: 1290: 1289: 1276: 1271: 1266: 1264: 1259: 1246: 1241: 1228: 1223: 1210: 1205: 1195: 1182: 1180: 1179: 1174: 1172: 1171: 1156:, and distances 1155: 1153: 1152: 1147: 1135: 1133: 1132: 1127: 1115: 1113: 1112: 1107: 1105: 1098: 1092: 1088: 1083: 1082: 1081: 1065: 1059: 1055: 1050: 1042: 1037: 1036: 1035: 1018: 1012: 1008: 1000: 992: 975: 966: 965: 946: 944: 943: 938: 936: 935: 934: 914: 912: 911: 906: 904: 903: 902: 882: 880: 879: 874: 859: 857: 856: 851: 826: 824: 823: 818: 816: 809: 808: 796: 792: 787: 765: 761: 760: 752: 729: 728: 716: 712: 711: 706: 683: 679: 671: 641: 639: 638: 633: 628: 627: 612: 610: 609: 604: 598: 597: 588: 580: 571: 570: 565: 561: 560: 559: 550: 541: 540: 530: 522: 507: 505: 504: 499: 494: 485: 484: 475: 473: 472: 467: 462: 461: 446: 441: 439: 438: 426: 422: 421: 420: 411: 402: 401: 375: 373: 372: 367: 355: 353: 352: 347: 330: 316:Hill tetrahedron 266:stella octangula 239:regular polygons 200: 188:stella octangula 183: 171: 134:convex polyhedra 94:convex polyhedra 63: 21: 17732: 17731: 17727: 17726: 17725: 17723: 17722: 17721: 17692:Platonic solids 17677: 17676: 17645: 17638: 17631: 17514: 17507: 17500: 17464: 17457: 17450: 17414: 17407: 17241:Regular polygon 17234: 17225: 17218: 17214: 17207: 17203: 17194: 17185: 17178: 17174: 17162: 17156: 17152: 17140: 17122: 17111: 17082: 17077: 17066: 17005:Dihedral others 16996: 16975: 16950: 16925: 16854: 16851: 16850: 16841: 16770: 16759: 16758: 16749: 16712: 16710:Platonic solids 16704: 16698: 16668: 16663: 16614: 16603:Star polyhedron 16585: 16550: 16498: 16475:Hexecontahedron 16457:Triacontahedron 16439: 16430:Enneadecahedron 16420:Heptadecahedron 16410:Pentadecahedron 16405:Tetradecahedron 16378: 16317: 16310: 16305: 16237: 16232: 16226: 16196: 16114: 16101: 16064:10.2307/3608204 16043: 16008:Coxeter, H.S.M. 15973: 15952: 15947: 15946: 15925: 15921: 15891: 15887: 15877: 15875: 15870: 15869: 15865: 15847: 15843: 15836: 15811: 15807: 15775: 15771: 15761: 15759: 15755: 15744: 15738: 15734: 15724: 15722: 15721:on 10 June 2007 15718: 15703: 15697: 15693: 15683: 15681: 15673: 15672: 15668: 15637: 15633: 15626: 15610: 15606: 15592: 15588: 15572: 15568: 15567: 15563: 15541: 15535: 15532: 15528: 15514: 15510: 15500: 15498: 15487: 15483: 15468: 15457: 15449: 15445: 15414: 15410: 15395:10.2307/2689983 15374: 15370: 15355: 15351: 15346:. Bulletin AMQ. 15343: 15337: 15333: 15317: 15316: 15311: 15303: 15299: 15294: 15290: 15275:10.2307/3647851 15246: 15240: 15236: 15228: 15224: 15216: 15212: 15204: 15197: 15193:, MathPages.com 15189: 15185: 15173: 15169: 15157: 15153: 15116: 15112: 15100: 15096: 15088: 15084: 15079: 15072: 15068: 15060: 15053: 15024:Coxeter, H.S.M. 15021: 15017: 15009: 15005: 14996: 14995: 14991: 14983: 14979: 14975: 14960: 14956: 14944: 14940: 14931: 14927: 14919: 14910: 14898: 14894: 14882: 14878: 14870: 14866: 14853: 14849: 14828: 14821: 14816: 14811: 14810: 14793: 14786: 14776:Plateau borders 14773: 14769: 14764: 14686: 14676: 14659:Platonic graphs 14656: 14648: 14502: 14467:Stanley Kubrick 14464: 14463: 14462: 14461: 14457: 14456: 14455: 14447: 14446: 14437: 14436: 14435: 14427: 14426: 14415: 14413:Popular culture 14399: 14393: 14373:polyhedral dice 14344: 14336: 14330: 14291: 14283:Main articles: 14281: 14241: 14238: 14237: 14236: 14234: 14221: 14218: 14215: 14214: 14212: 14197: 14194: 14193: 14192: 14190: 14181: 14178: 14177: 14176: 14174: 14161:molecules. All 14155: 14126: 14114: 14102: 14034: 14029: 13965: 13960: 13951: 13946: 13937: 13932: 13757: 13562:Compact hyper. 13551: 13343: 13338: 13333: 13328: 13323: 13321: 13314: 13309: 13304: 13299: 13294: 13292: 13285: 13280: 13275: 13270: 13265: 13263: 13256: 13251: 13246: 13241: 13236: 13234: 13227: 13222: 13217: 13212: 13207: 13205: 13198: 13193: 13188: 13183: 13178: 13176: 13169: 13164: 13159: 13154: 13149: 13147: 13140: 13135: 13130: 13125: 13120: 13118: 12854: 12655: 12648: 12639:Antiprism name 12634: 12423: 12410: 12407: 12405: 12400: 12398: 12393: 12391: 12380: 12374: 12366: 12354:arithmetic mean 12350: 12328: 12327: 12320: 12319: 12313: 12309: 12303: 12299: 12287: 12283: 12277: 12273: 12267: 12266: 12260: 12256: 12250: 12246: 12234: 12230: 12224: 12220: 12214: 12213: 12207: 12203: 12197: 12193: 12181: 12177: 12171: 12167: 12160: 12156: 12146: 12138: 12133: 12128: 12126: 12121: 12114: 12113: 12107: 12096: 12092: 12083: 12079: 12078: 12074: 12073: 12070: 12069: 12063: 12052: 12048: 12039: 12035: 12034: 12030: 12029: 12026: 12025: 12019: 12008: 12004: 11995: 11991: 11990: 11986: 11985: 11981: 11977: 11969: 11964: 11959: 11957: 11945: 11941: 11934: 11927: 11925: 11922: 11921: 11915: 11909: 11906: 11900: 11897: 11891: 11888: 11882: 11876: 11872: 11843: 11716: 11708: 11705: 11704: 11666: 11641: 11637: 11627: 11615: 11611: 11601: 11589: 11585: 11575: 11563: 11559: 11549: 11541: 11538: 11537: 11512: 11508: 11499: 11495: 11486: 11482: 11473: 11469: 11468: 11460: 11458: 11450: 11447: 11446: 11437: 11428: 11419: 11410: 11375: 11371: 11366: 11355: 11350: 11341: 11330: 11325: 11316: 11305: 11300: 11291: 11280: 11275: 11266: 11264: 11261: 11260: 11251: 11233: 11134: 11131: 11130: 11054: 11053: 11049: 11030: 11029: 11025: 11006: 11005: 11001: 10982: 10981: 10977: 10966: 10963: 10962: 10957: 10950: 10943: 10936: 10904: 10877: 10873: 10861: 10857: 10851: 10847: 10835: 10831: 10819: 10815: 10809: 10805: 10793: 10789: 10777: 10773: 10767: 10763: 10748: 10743: 10730: 10725: 10712: 10707: 10694: 10689: 10683: 10680: 10679: 10658: 10654: 10648: 10644: 10642: 10639: 10638: 10618: 10614: 10612: 10609: 10608: 10591: 10587: 10585: 10582: 10581: 10564: 10560: 10558: 10555: 10554: 10537: 10533: 10531: 10528: 10527: 10510: 10506: 10504: 10501: 10500: 10483: 10479: 10477: 10474: 10473: 10456: 10452: 10450: 10447: 10446: 10443: 10437: 10272: 10269: 10268: 10242: 10229: 10165:Thomson problem 10153: 10085:Lorenz Lindelöf 10066: 10034: 10033: 10025: 10015: 10011: 10007: 9999: 9989: 9985: 9981: 9973: 9963: 9959: 9955: 9946: 9945: 9935: 9931: 9927: 9919: 9911: 9901: 9897: 9893: 9885: 9875: 9871: 9867: 9858: 9857: 9847: 9843: 9839: 9831: 9821: 9817: 9813: 9805: 9797: 9787: 9783: 9779: 9770: 9769: 9759: 9755: 9751: 9743: 9733: 9729: 9725: 9717: 9707: 9703: 9699: 9691: 9678: 9677: 9675: 9672: 9671: 9630:of a triangle. 9570: 9541: 9521: 9513: 9505: 9501: 9499: 9491: 9488: 9487: 9471: 9468: 9467: 9447: 9439: 9437: 9434: 9433: 9417: 9414: 9413: 9397: 9394: 9393: 9379:dihedral angles 9347: 9346: 9291: 9237: 9236: 9182: 9128: 9127: 9073: 9018: 9016: 9013: 9012: 8998: 8997: 8981: 8972: 8956: 8947: 8946: 8930: 8921: 8905: 8895: 8893: 8890: 8889: 8859: 8740: 8732: 8729: 8728: 8712: 8709: 8708: 8692: 8689: 8688: 8672: 8669: 8668: 8652: 8649: 8648: 8632: 8629: 8628: 8612: 8609: 8608: 8592: 8589: 8588: 8572: 8569: 8568: 8552: 8549: 8548: 8532: 8529: 8528: 8512: 8509: 8508: 8492: 8489: 8488: 8460: 8451: 8447: 8439: 8430: 8426: 8418: 8409: 8405: 8397: 8386: 8375: 8358: 8342: 8340: 8332: 8329: 8328: 8314: 8313: 8304: 8300: 8291: 8287: 8278: 8274: 8267: 8261: 8260: 8251: 8247: 8238: 8234: 8225: 8221: 8214: 8208: 8207: 8198: 8194: 8185: 8181: 8172: 8168: 8161: 8154: 8152: 8149: 8148: 8113: 8109: 8103: 8099: 8090: 8086: 8080: 8076: 8067: 8063: 8057: 8053: 8044: 8040: 8034: 8030: 8024: 8020: 8014: 8006: 8003: 8002: 7986: 7983: 7982: 7966: 7963: 7962: 7946: 7943: 7942: 7926: 7923: 7922: 7906: 7903: 7902: 7886: 7883: 7882: 7866: 7863: 7862: 7856:Heron's formula 7843: 7819: 7808: 7787: 7786: 7781: 7775: 7770: 7764: 7758: 7753: 7747: 7741: 7736: 7730: 7724: 7723: 7717: 7712: 7706: 7701: 7695: 7690: 7684: 7678: 7673: 7667: 7661: 7660: 7654: 7649: 7643: 7637: 7632: 7626: 7621: 7615: 7610: 7604: 7598: 7597: 7591: 7586: 7580: 7574: 7569: 7563: 7557: 7552: 7546: 7541: 7535: 7534: 7529: 7524: 7519: 7514: 7504: 7503: 7494: 7490: 7482: 7479: 7478: 7441: 7440: 7435: 7430: 7425: 7419: 7418: 7412: 7408: 7406: 7400: 7396: 7394: 7388: 7384: 7382: 7376: 7372: 7369: 7368: 7362: 7358: 7356: 7350: 7346: 7344: 7338: 7334: 7332: 7326: 7322: 7319: 7318: 7312: 7308: 7306: 7300: 7296: 7294: 7288: 7284: 7282: 7276: 7272: 7268: 7264: 7260: 7256: 7242: 7239: 7238: 7147: 7138: 7134: 7126: 7117: 7113: 7105: 7096: 7092: 7084: 7073: 7062: 7045: 7029: 7027: 7019: 7016: 7015: 6994: 6993: 6988: 6981: 6980: 6972: 6969: 6968: 6950: 6949: 6944: 6937: 6936: 6928: 6925: 6924: 6906: 6905: 6900: 6893: 6892: 6884: 6881: 6880: 6860: 6859: 6851: 6831: 6823: 6820: 6819: 6811: 6791: 6783: 6780: 6779: 6771: 6751: 6743: 6736: 6735: 6733: 6730: 6729: 6726: 6722: 6705: 6704: 6697: 6693: 6692: 6690: 6685: 6677: 6675: 6670: 6662: 6659: 6658: 6653: 6645: 6643: 6636: 6632: 6631: 6629: 6624: 6616: 6613: 6612: 6607: 6599: 6597: 6592: 6584: 6582: 6575: 6571: 6570: 6563: 6562: 6553: 6549: 6541: 6538: 6537: 6526: 6510: 6509: 6497: 6493: 6484: 6480: 6471: 6467: 6456: 6453: 6452: 6440: 6436: 6427: 6423: 6414: 6410: 6399: 6396: 6395: 6383: 6379: 6370: 6366: 6357: 6353: 6342: 6335: 6334: 6332: 6329: 6328: 6325: 6321: 6304: 6303: 6298: 6295: 6294: 6289: 6286: 6285: 6280: 6273: 6272: 6258: 6255: 6254: 6251: 6247: 6230: 6229: 6224: 6222: 6217: 6215: 6210: 6203: 6202: 6188: 6185: 6184: 6171: 6168: 6165: 6164: 6162: 6135: 6127: 6119: 6111: 6103: 6095: 6079: 6077: 6074: 6073: 6056: 6055: 6043: 6039: 6030: 6026: 6017: 6013: 6003: 5998: 5995: 5994: 5982: 5978: 5969: 5965: 5956: 5952: 5942: 5937: 5934: 5933: 5921: 5917: 5908: 5904: 5895: 5891: 5881: 5876: 5873: 5872: 5860: 5856: 5847: 5843: 5834: 5830: 5820: 5815: 5811: 5809: 5806: 5805: 5785: 5782: 5781: 5761: 5758: 5757: 5727: 5719: 5716: 5715: 5712: 5707: 5681: 5676: 5674: 5671: 5670: 5650: 5633: 5621: 5610: 5602: 5584: 5570: 5565: 5561: 5558: 5552: 5551: 5540: 5530: 5522: 5508: 5480: 5464: 5459: 5454: 5449: 5444: 5442: 5440: 5433: 5426: 5415: 5391: 5386: 5382: 5379: 5375: 5374: 5358: 5353: 5348: 5343: 5338: 5336: 5334: 5325: 5286: 5271: 5258: 5244: 5237: 5236: 5229: 5228: 5217: 5206: 5199: 5177: 5172: 5168: 5165: 5161: 5160: 5149: 5141:symmetric group 5138: 5130: 5104: 5099: 5095: 5089: 5088: 5076:Schläfli symbol 5069: 5064: 5059: 5054: 5049: 5047: 5045:Coxeter diagram 5042: 5034:symmetric group 5031: 5024: 4970: 4968: 4957: 4953: 4944: 4877: 4846:Hill tetrahedra 4834: 4803: 4801: 4798: 4797: 4770: 4768: 4765: 4764: 4737: 4735: 4732: 4731: 4704: 4702: 4699: 4698: 4671: 4669: 4666: 4665: 4638: 4636: 4633: 4632: 4605: 4603: 4600: 4599: 4572: 4570: 4567: 4566: 4548: 4545: 4544: 4513: 4511: 4508: 4507: 4480: 4478: 4475: 4474: 4456: 4453: 4452: 4421: 4419: 4416: 4415: 4388: 4386: 4383: 4382: 4355: 4353: 4350: 4349: 4318: 4316: 4313: 4312: 4294: 4291: 4290: 4263: 4261: 4258: 4257: 4220: 4219: 4216: 4214: 4211: 4210: 4184: 4182: 4179: 4178: 4122: 4120: 4117: 4116: 4094: 4085: 4082: 4080: 4077: 4076: 4032: 4030: 4027: 4026: 4004: 3995: 3992: 3990: 3987: 3986: 3942: 3940: 3937: 3936: 3914: 3905: 3902: 3900: 3897: 3896: 3856: 3854: 3851: 3850: 3826: 3811: 3809: 3806: 3805: 3766: 3764: 3761: 3760: 3729: 3727: 3724: 3723: 3699: 3684: 3682: 3679: 3678: 3654: 3651: 3650: 3619: 3617: 3614: 3613: 3589: 3584: 3581: 3580: 3541: 3539: 3536: 3535: 3499: 3488: 3485: 3484: 3460: 3449: 3446: 3445: 3421: 3418: 3417: 3384: 3379: 3374: 3369: 3364: 3362: 3356: 3351: 3346: 3341: 3336: 3334: 3314: 3312: 3306: 3301: 3296: 3291: 3286: 3284: 3278: 3273: 3268: 3263: 3258: 3256: 3251: 3249: 3244: 3242: 3225:name for it is 3199:right triangles 3183: 3166:dihedral angles 3158: 3152: 3118: 3112: 3054: 3045: 3035: 3007:four dimensions 2976: 2924: 2869: 2855: 2809: 2796: 2760: 2756: 2746: 2743: 2729: 2728: 2726: 2722: 2691: 2687: 2685: 2682: 2681: 2662: 2660: 2657: 2656: 2635: 2631: 2629: 2626: 2625: 2623:symmetric group 2600: 2599: 2594: 2593: 2591: 2588: 2587: 2566:point inversion 2546: 2510: 2508: 2505: 2504: 2502:Schläfli symbol 2495: 2490: 2485: 2480: 2475: 2473: 2471:Coxeter diagram 2440: 2435: 2432: 2431: 2417: 2416: 2381: 2348: 2347: 2312: 2284: 2282: 2279: 2278: 2243: 2239: 2237: 2235: 2232: 2231: 2217: 2216: 2190: 2172: 2154: 2136: 2132: 2128: 2125: 2124: 2106: 2088: 2073: 2069: 2065: 2062: 2044: 2020: 2019: 2015: 2011: 2009: 2006: 2005: 1986: 1983: 1982: 1948: 1932: 1928: 1920: 1902: 1883: 1879: 1877: 1874: 1873: 1866: 1835: 1834: 1814: 1810: 1792: 1791: 1777: 1773: 1751: 1744: 1730: 1726: 1716: 1714: 1711: 1710: 1665: 1663: 1658: 1656: 1636: 1635: 1626: 1615: 1610: 1597: 1592: 1579: 1574: 1561: 1556: 1543: 1539: 1538: 1534: 1533: 1526: 1515: 1510: 1497: 1492: 1479: 1474: 1461: 1456: 1443: 1439: 1438: 1434: 1428: 1427: 1418: 1401: 1397: 1393: 1391: 1376: 1371: 1358: 1353: 1340: 1335: 1322: 1317: 1312: 1310: 1309: 1305: 1304: 1297: 1285: 1281: 1277: 1275: 1260: 1255: 1242: 1237: 1224: 1219: 1206: 1201: 1196: 1194: 1190: 1188: 1185: 1184: 1167: 1163: 1161: 1158: 1157: 1141: 1138: 1137: 1121: 1118: 1117: 1103: 1102: 1087: 1077: 1076: 1072: 1069: 1054: 1041: 1031: 1030: 1026: 1023: 1022: 1007: 991: 982: 964: 954: 952: 949: 948: 930: 929: 925: 923: 920: 919: 898: 897: 893: 891: 888: 887: 868: 865: 864: 845: 842: 841: 814: 813: 804: 800: 786: 782: 766: 751: 747: 743: 734: 733: 724: 720: 705: 701: 697: 684: 670: 666: 656: 654: 651: 650: 623: 619: 603: 599: 593: 589: 587: 569: 555: 551: 539: 538: 534: 521: 513: 510: 509: 483: 481: 478: 477: 457: 453: 440: 434: 430: 416: 412: 400: 399: 395: 381: 378: 377: 361: 358: 357: 341: 338: 337: 324: 235:Platonic solids 212: 211: 210: 209: 208: 201: 192: 191: 190: 184: 176: 175: 172: 161: 84:, six straight 48: 28: 23: 22: 15: 12: 11: 5: 17730: 17720: 17719: 17714: 17709: 17704: 17699: 17694: 17689: 17673: 17672: 17657: 17656: 17647: 17643: 17636: 17629: 17625: 17616: 17599: 17590: 17579: 17578: 17576: 17574: 17569: 17560: 17555: 17549: 17548: 17546: 17544: 17539: 17530: 17525: 17519: 17518: 17516: 17512: 17505: 17498: 17494: 17489: 17480: 17475: 17469: 17468: 17466: 17462: 17455: 17448: 17444: 17439: 17430: 17425: 17419: 17418: 17416: 17412: 17405: 17401: 17396: 17387: 17382: 17376: 17375: 17373: 17371: 17366: 17357: 17352: 17346: 17345: 17336: 17331: 17326: 17317: 17312: 17306: 17305: 17296: 17294: 17289: 17280: 17275: 17269: 17268: 17263: 17258: 17253: 17248: 17243: 17237: 17236: 17232: 17228: 17223: 17212: 17201: 17192: 17183: 17176: 17170: 17160: 17154: 17148: 17142: 17136: 17130: 17124: 17123: 17112: 17110: 17109: 17102: 17095: 17087: 17079: 17078: 17071: 17068: 17067: 17065: 17064: 17059: 17054: 17049: 17044: 17039: 17034: 17029: 17024: 17019: 17014: 17008: 17006: 17002: 17001: 16998: 16997: 16995: 16994: 16989: 16983: 16981: 16977: 16976: 16974: 16973: 16968: 16962: 16956: 16952: 16951: 16949: 16948: 16941: 16933: 16931: 16927: 16926: 16924: 16923: 16918: 16913: 16908: 16903: 16898: 16893: 16888: 16883: 16878: 16873: 16868: 16863: 16857: 16855: 16848:Catalan solids 16846: 16843: 16842: 16840: 16839: 16834: 16829: 16824: 16819: 16814: 16809: 16804: 16799: 16794: 16789: 16787:truncated cube 16784: 16779: 16773: 16771: 16754: 16751: 16750: 16748: 16747: 16742: 16737: 16732: 16727: 16721: 16719: 16706: 16705: 16697: 16696: 16689: 16682: 16674: 16665: 16664: 16662: 16661: 16659:parallelepiped 16656: 16651: 16646: 16641: 16636: 16631: 16625: 16623: 16616: 16615: 16613: 16612: 16606: 16600: 16593: 16591: 16587: 16586: 16584: 16583: 16577: 16571: 16565: 16562:Platonic solid 16558: 16556: 16552: 16551: 16549: 16548: 16547: 16546: 16540: 16534: 16522: 16517: 16512: 16506: 16504: 16500: 16499: 16497: 16496: 16490: 16484: 16478: 16472: 16466: 16460: 16454: 16447: 16445: 16441: 16440: 16438: 16437: 16432: 16427: 16425:Octadecahedron 16422: 16417: 16415:Hexadecahedron 16412: 16407: 16402: 16397: 16392: 16386: 16384: 16380: 16379: 16377: 16376: 16371: 16366: 16361: 16356: 16351: 16346: 16341: 16336: 16331: 16325: 16323: 16319: 16318: 16315: 16312: 16311: 16304: 16303: 16296: 16289: 16281: 16275: 16274: 16262: 16257: 16236: 16235:External links 16233: 16231: 16230: 16224: 16211: 16189: 16161:(2): 379–400. 16146: 16133: 16119: 16105: 16099: 16084: 16047: 16041: 16022: 16004: 15990: 15977: 15971: 15953: 15951: 15948: 15945: 15944: 15919: 15885: 15863: 15841: 15834: 15814:Holmes, Arthur 15805: 15769: 15758:on 7 June 2011 15732: 15691: 15666: 15631: 15624: 15604: 15586: 15561: 15539: 15526: 15508: 15481: 15455: 15443: 15408: 15368: 15349: 15331: 15297: 15288: 15259:(8): 679–693. 15234: 15222: 15210: 15195: 15183: 15167: 15151: 15110: 15094: 15082: 15077: 15066: 15051: 15038:(1–3): 59–71. 15015: 15013:, p. 181. 15003: 14989: 14977: 14974: 14973: 14968: 14961: 14954: 14938: 14925: 14908: 14892: 14884:Shavinina 2013 14876: 14864: 14847: 14818: 14817: 14815: 14812: 14809: 14808: 14784: 14766: 14765: 14763: 14760: 14759: 14758: 14753: 14748: 14742: 14737: 14732: 14727: 14722: 14716: 14702: 14697: 14692: 14685: 14682: 14679: 14678: 14663:Platonic solid 14654: 14646: 14643:complete graph 14629: 14628: 14622: 14621: 14592: 14588: 14587: 14584: 14578: 14577: 14574: 14568: 14567: 14564: 14558: 14557: 14554: 14548: 14547: 14544: 14538: 14537: 14534: 14528: 14527: 14524: 14518: 14517: 14509: 14508: 14501: 14498: 14459: 14458: 14449: 14448: 14440: 14439: 14438: 14429: 14428: 14420: 14419: 14418: 14417: 14416: 14414: 14411: 14395:Main article: 14392: 14389: 14363:Especially in 14343: 14340: 14332:Main article: 14329: 14326: 14280: 14277: 14251:phase diagrams 14239: 14195: 14179: 14151:Main article: 14125: 14122: 14113: 14110: 14101: 14098: 14054:polygonal mesh 14033: 14030: 14028: 14025: 13967: 13966: 13961: 13954: 13952: 13947: 13940: 13938: 13933: 13926: 13924: 13918: 13917: 13914: 13911: 13908: 13905: 13900: 13895: 13890: 13885: 13880: 13875: 13870: 13864: 13863: 13856: 13849: 13842: 13835: 13828: 13821: 13814: 13807: 13800: 13793: 13786: 13778: 13777: 13774: 13771: 13768: 13763: 13759: 13758: 13756: 13755: 13748: 13741: 13733: 13716:vertex figures 13710: 13709: 13706: 13703: 13700: 13697: 13692: 13687: 13682: 13677: 13672: 13667: 13662: 13656: 13655: 13648: 13641: 13634: 13627: 13620: 13613: 13606: 13599: 13592: 13585: 13578: 13570: 13569: 13566: 13563: 13560: 13557: 13553: 13552: 13550: 13549: 13542: 13535: 13527: 13496: 13495: 13490: 13485: 13480: 13475: 13470: 13465: 13460: 13454: 13453: 13446: 13439: 13432: 13425: 13418: 13411: 13404: 13396: 13395: 13391: 13390: 13385: 13380: 13375: 13370: 13365: 13360: 13355: 13349: 13348: 13319: 13290: 13261: 13232: 13203: 13174: 13145: 13115: 13114: 13107: 13100: 13093: 13086: 13079: 13072: 13065: 13057: 13056: 13053: 13043: 13042: 13021: 13020: 13017: 13014: 13011: 13008: 13005: 13002: 12999: 12993: 12992: 12985: 12979: 12972: 12965: 12958: 12951: 12944: 12937: 12936: 12934: 12931: 12924: 12917: 12910: 12903: 12896: 12889: 12888: 12883: 12880: 12875: 12870: 12865: 12860: 12851: 12823: 12822: 12819: 12816: 12813: 12810: 12807: 12804: 12801: 12798: 12796:Vertex config. 12792: 12791: 12784: 12781: 12774: 12767: 12760: 12753: 12746: 12739: 12735: 12734: 12732: 12729: 12722: 12715: 12708: 12701: 12694: 12687: 12683: 12682: 12677: 12674: 12669: 12664: 12659: 12652: 12645: 12640: 12633: 12632: 12625: 12618: 12610: 12580: 12579: 12576: 12569: 12562: 12555: 12548: 12541: 12533: 12532: 12529: 12522: 12515: 12508: 12501: 12494: 12486: 12485: 12482: 12479: 12476: 12472: 12471: 12468: 12465: 12460: 12455: 12450: 12445: 12439: 12438: 12422: 12419: 12390:with areas of 12376:Main article: 12373: 12370: 12365: 12362: 12349: 12346: 12342: 12341: 12325: 12316: 12312: 12306: 12302: 12298: 12295: 12290: 12286: 12280: 12276: 12272: 12269: 12268: 12263: 12259: 12253: 12249: 12245: 12242: 12237: 12233: 12227: 12223: 12219: 12216: 12215: 12210: 12206: 12200: 12196: 12192: 12189: 12184: 12180: 12174: 12170: 12166: 12163: 12162: 12159: 12153: 12150: 12145: 12142: 12139: 12134: 12127: 12122: 12119: 12110: 12105: 12099: 12095: 12091: 12086: 12082: 12077: 12072: 12071: 12066: 12061: 12055: 12051: 12047: 12042: 12038: 12033: 12028: 12027: 12022: 12017: 12011: 12007: 12003: 11998: 11994: 11989: 11984: 11983: 11980: 11976: 11973: 11970: 11965: 11958: 11956: 11951: 11948: 11944: 11940: 11937: 11935: 11933: 11930: 11929: 11913: 11904: 11895: 11886: 11871: 11868: 11867: 11866: 11855: 11849: 11846: 11841: 11838: 11835: 11832: 11829: 11826: 11823: 11820: 11817: 11814: 11811: 11808: 11805: 11802: 11799: 11796: 11793: 11790: 11787: 11784: 11781: 11778: 11775: 11772: 11769: 11766: 11763: 11760: 11757: 11754: 11751: 11748: 11745: 11742: 11739: 11736: 11733: 11730: 11727: 11724: 11721: 11715: 11712: 11665: 11662: 11649: 11644: 11640: 11634: 11631: 11626: 11623: 11618: 11614: 11608: 11605: 11600: 11597: 11592: 11588: 11582: 11579: 11574: 11571: 11566: 11562: 11556: 11553: 11548: 11545: 11533: 11532: 11515: 11511: 11507: 11502: 11498: 11494: 11489: 11485: 11481: 11476: 11472: 11466: 11463: 11457: 11454: 11433: 11424: 11415: 11406: 11397: 11396: 11385: 11378: 11374: 11370: 11365: 11358: 11353: 11349: 11345: 11340: 11333: 11328: 11324: 11320: 11315: 11308: 11303: 11299: 11295: 11290: 11283: 11278: 11274: 11270: 11247: 11232: 11229: 11228: 11227: 11216: 11213: 11210: 11207: 11204: 11201: 11198: 11195: 11192: 11189: 11186: 11183: 11180: 11177: 11174: 11171: 11168: 11165: 11162: 11159: 11156: 11153: 11150: 11147: 11144: 11141: 11138: 11084: 11083: 11072: 11069: 11066: 11063: 11057: 11052: 11048: 11045: 11042: 11039: 11033: 11028: 11024: 11021: 11018: 11015: 11009: 11004: 11000: 10997: 10994: 10991: 10985: 10980: 10976: 10973: 10970: 10955: 10948: 10941: 10934: 10903: 10902:Interior point 10900: 10888: 10883: 10880: 10876: 10872: 10869: 10864: 10860: 10854: 10850: 10846: 10841: 10838: 10834: 10830: 10827: 10822: 10818: 10812: 10808: 10804: 10799: 10796: 10792: 10788: 10785: 10780: 10776: 10770: 10766: 10762: 10759: 10756: 10751: 10746: 10742: 10738: 10733: 10728: 10724: 10720: 10715: 10710: 10706: 10702: 10697: 10692: 10688: 10676:law of cosines 10661: 10657: 10651: 10647: 10624: 10621: 10617: 10594: 10590: 10567: 10563: 10540: 10536: 10513: 10509: 10486: 10482: 10459: 10455: 10439:Main article: 10436: 10433: 10412: 10411: 10399: 10396: 10393: 10390: 10387: 10384: 10381: 10378: 10375: 10372: 10369: 10366: 10363: 10360: 10357: 10354: 10351: 10348: 10345: 10342: 10339: 10336: 10333: 10330: 10327: 10324: 10321: 10318: 10315: 10312: 10309: 10306: 10303: 10300: 10297: 10294: 10291: 10288: 10285: 10282: 10279: 10276: 10238:Main article: 10228: 10225: 10152: 10149: 10127:coincide with 10064: 10059: 10058: 10046: 10043: 10038: 10032: 10029: 10026: 10023: 10018: 10014: 10010: 10006: 10003: 10000: 9997: 9992: 9988: 9984: 9980: 9977: 9974: 9971: 9966: 9962: 9958: 9954: 9951: 9948: 9947: 9943: 9938: 9934: 9930: 9926: 9923: 9920: 9918: 9915: 9912: 9909: 9904: 9900: 9896: 9892: 9889: 9886: 9883: 9878: 9874: 9870: 9866: 9863: 9860: 9859: 9855: 9850: 9846: 9842: 9838: 9835: 9832: 9829: 9824: 9820: 9816: 9812: 9809: 9806: 9804: 9801: 9798: 9795: 9790: 9786: 9782: 9778: 9775: 9772: 9771: 9767: 9762: 9758: 9754: 9750: 9747: 9744: 9741: 9736: 9732: 9728: 9724: 9721: 9718: 9715: 9710: 9706: 9702: 9698: 9695: 9692: 9690: 9687: 9684: 9683: 9681: 9575:Spieker center 9569: 9566: 9554: 9549: 9544: 9540: 9536: 9533: 9530: 9527: 9524: 9520: 9516: 9512: 9508: 9504: 9498: 9495: 9475: 9462:as calculated 9450: 9446: 9442: 9421: 9401: 9345: 9342: 9339: 9336: 9333: 9330: 9327: 9324: 9320: 9317: 9314: 9311: 9308: 9305: 9302: 9299: 9296: 9292: 9290: 9287: 9284: 9281: 9278: 9275: 9272: 9269: 9266: 9263: 9260: 9257: 9254: 9251: 9248: 9245: 9242: 9239: 9238: 9235: 9232: 9229: 9226: 9223: 9220: 9217: 9214: 9211: 9208: 9205: 9202: 9199: 9196: 9193: 9190: 9187: 9183: 9181: 9178: 9175: 9172: 9169: 9166: 9163: 9160: 9157: 9154: 9151: 9148: 9145: 9142: 9139: 9136: 9133: 9130: 9129: 9126: 9123: 9120: 9117: 9114: 9111: 9108: 9105: 9102: 9099: 9096: 9093: 9090: 9087: 9084: 9081: 9078: 9074: 9072: 9069: 9066: 9063: 9060: 9057: 9054: 9051: 9048: 9045: 9042: 9039: 9036: 9033: 9030: 9027: 9024: 9021: 9020: 8996: 8991: 8988: 8985: 8980: 8977: 8973: 8971: 8966: 8963: 8960: 8955: 8952: 8949: 8948: 8945: 8940: 8937: 8934: 8929: 8926: 8922: 8920: 8915: 8912: 8909: 8904: 8901: 8898: 8897: 8874: 8870: 8866: 8862: 8857: 8854: 8851: 8848: 8845: 8842: 8839: 8836: 8833: 8829: 8826: 8823: 8820: 8817: 8814: 8811: 8808: 8805: 8801: 8798: 8795: 8792: 8789: 8786: 8783: 8780: 8777: 8773: 8770: 8767: 8764: 8761: 8758: 8755: 8752: 8749: 8746: 8739: 8736: 8716: 8696: 8676: 8656: 8636: 8616: 8596: 8576: 8556: 8536: 8516: 8496: 8463: 8459: 8454: 8450: 8446: 8442: 8438: 8433: 8429: 8425: 8421: 8417: 8412: 8408: 8404: 8400: 8396: 8393: 8389: 8385: 8382: 8378: 8374: 8371: 8368: 8365: 8362: 8355: 8351: 8348: 8345: 8339: 8336: 8312: 8307: 8303: 8299: 8294: 8290: 8286: 8281: 8277: 8273: 8270: 8268: 8266: 8263: 8262: 8259: 8254: 8250: 8246: 8241: 8237: 8233: 8228: 8224: 8220: 8217: 8215: 8213: 8210: 8209: 8206: 8201: 8197: 8193: 8188: 8184: 8180: 8175: 8171: 8167: 8164: 8162: 8160: 8157: 8156: 8134: 8130: 8127: 8124: 8121: 8116: 8112: 8106: 8102: 8098: 8093: 8089: 8083: 8079: 8075: 8070: 8066: 8060: 8056: 8052: 8047: 8043: 8037: 8033: 8027: 8023: 8019: 8013: 8010: 7990: 7970: 7950: 7930: 7910: 7890: 7870: 7841: 7816:∈ {1, 2, 3, 4} 7805: 7804: 7791: 7785: 7782: 7778: 7773: 7769: 7765: 7761: 7756: 7752: 7748: 7744: 7739: 7735: 7731: 7729: 7726: 7725: 7720: 7715: 7711: 7707: 7705: 7702: 7698: 7693: 7689: 7685: 7681: 7676: 7672: 7668: 7666: 7663: 7662: 7657: 7652: 7648: 7644: 7640: 7635: 7631: 7627: 7625: 7622: 7618: 7613: 7609: 7605: 7603: 7600: 7599: 7594: 7589: 7585: 7581: 7577: 7572: 7568: 7564: 7560: 7555: 7551: 7547: 7545: 7542: 7540: 7537: 7536: 7533: 7530: 7528: 7525: 7523: 7520: 7518: 7515: 7513: 7510: 7509: 7507: 7502: 7497: 7493: 7489: 7486: 7468: 7467: 7456: 7451: 7446: 7439: 7436: 7434: 7431: 7429: 7426: 7424: 7421: 7420: 7415: 7411: 7407: 7403: 7399: 7395: 7391: 7387: 7383: 7379: 7375: 7371: 7370: 7365: 7361: 7357: 7353: 7349: 7345: 7341: 7337: 7333: 7329: 7325: 7321: 7320: 7315: 7311: 7307: 7303: 7299: 7295: 7291: 7287: 7283: 7279: 7275: 7271: 7270: 7267: 7263: 7259: 7255: 7252: 7249: 7246: 7169: 7168: 7156: 7150: 7146: 7141: 7137: 7133: 7129: 7125: 7120: 7116: 7112: 7108: 7104: 7099: 7095: 7091: 7087: 7083: 7080: 7076: 7072: 7069: 7065: 7061: 7058: 7055: 7052: 7049: 7042: 7038: 7035: 7032: 7026: 7023: 7011:, which gives 6998: 6991: 6987: 6986: 6984: 6979: 6976: 6954: 6947: 6943: 6942: 6940: 6935: 6932: 6910: 6903: 6899: 6898: 6896: 6891: 6888: 6877: 6876: 6863: 6858: 6854: 6850: 6847: 6844: 6841: 6838: 6834: 6830: 6826: 6822: 6821: 6818: 6814: 6810: 6807: 6804: 6801: 6798: 6794: 6790: 6786: 6782: 6781: 6778: 6774: 6770: 6767: 6764: 6761: 6758: 6754: 6750: 6746: 6742: 6741: 6739: 6709: 6700: 6696: 6691: 6688: 6684: 6680: 6676: 6673: 6669: 6665: 6661: 6660: 6656: 6652: 6648: 6644: 6639: 6635: 6630: 6627: 6623: 6619: 6615: 6614: 6610: 6606: 6602: 6598: 6595: 6591: 6587: 6583: 6578: 6574: 6569: 6568: 6566: 6561: 6556: 6552: 6548: 6545: 6531: 6530: 6513: 6508: 6505: 6500: 6496: 6492: 6487: 6483: 6479: 6474: 6470: 6466: 6463: 6459: 6455: 6454: 6451: 6448: 6443: 6439: 6435: 6430: 6426: 6422: 6417: 6413: 6409: 6406: 6402: 6398: 6397: 6394: 6391: 6386: 6382: 6378: 6373: 6369: 6365: 6360: 6356: 6352: 6349: 6345: 6341: 6340: 6338: 6308: 6301: 6297: 6296: 6292: 6288: 6287: 6283: 6279: 6278: 6276: 6271: 6268: 6265: 6262: 6234: 6227: 6223: 6220: 6216: 6213: 6209: 6208: 6206: 6201: 6198: 6195: 6192: 6159:parallelepiped 6142: 6138: 6134: 6130: 6126: 6122: 6118: 6114: 6110: 6106: 6102: 6098: 6094: 6091: 6086: 6083: 6054: 6051: 6046: 6042: 6038: 6033: 6029: 6025: 6020: 6016: 6012: 6009: 6006: 6004: 6001: 5997: 5996: 5993: 5990: 5985: 5981: 5977: 5972: 5968: 5964: 5959: 5955: 5951: 5948: 5945: 5943: 5940: 5936: 5935: 5932: 5929: 5924: 5920: 5916: 5911: 5907: 5903: 5898: 5894: 5890: 5887: 5884: 5882: 5879: 5875: 5874: 5871: 5868: 5863: 5859: 5855: 5850: 5846: 5842: 5837: 5833: 5829: 5826: 5823: 5821: 5818: 5814: 5813: 5789: 5765: 5745: 5742: 5739: 5734: 5731: 5726: 5723: 5711: 5708: 5706: 5703: 5688: 5684: 5680: 5649: 5646: 5643: 5642: 5639: 5636: 5634: 5631: 5625: 5624: 5619: 5608: 5592: 5590: 5577: 5573: 5572: 5567: 5562: 5559: 5556: 5549: 5543: 5542: 5538: 5528: 5516: 5514: 5501: 5495: 5494: 5490: 5489: 5486: 5483: 5481: 5478: 5472: 5471: 5438: 5431: 5424: 5409: 5407: 5400: 5394: 5393: 5388: 5383: 5380: 5377: 5372: 5366: 5365: 5332: 5319: 5317: 5310: 5304: 5303: 5296: 5295: 5292: 5289: 5287: 5284: 5280: 5279: 5269: 5267: 5260: 5259:(No symmetry) 5254: 5253: 5250: 5247: 5245: 5242: 5234: 5226: 5220: 5219: 5215: 5204: 5193: 5191: 5184: 5180: 5179: 5174: 5169: 5166: 5163: 5158: 5152: 5151: 5147: 5136: 5129:triangle sides 5120: 5118: 5111: 5107: 5106: 5101: 5096: 5093: 5086: 5080: 5079: 5040: 5029: 5018: 5016: 5009: 5005: 5004: 4999: 4994: 4989: 4983: 4982: 4976: 4975: 4972: 4965: 4955: 4951: 4943: 4940: 4893:symmetry group 4876: 4873: 4833: 4830: 4812: 4809: 4779: 4776: 4746: 4743: 4713: 4710: 4680: 4677: 4647: 4644: 4614: 4611: 4581: 4578: 4552: 4522: 4519: 4489: 4486: 4460: 4430: 4427: 4397: 4394: 4364: 4361: 4327: 4324: 4298: 4272: 4269: 4251: 4250: 4248: 4246: 4231: 4227: 4207: 4202: 4200: 4174: 4173: 4171: 4169: 4167: 4165: 4162: 4161: 4159: 4157: 4155: 4153: 4141: 4138: 4131: 4128: 4113: 4101: 4097: 4093: 4088: 4084: 4072: 4071: 4069: 4067: 4065: 4063: 4051: 4048: 4041: 4038: 4023: 4011: 4007: 4003: 3998: 3994: 3982: 3981: 3979: 3977: 3975: 3973: 3961: 3958: 3951: 3948: 3933: 3921: 3917: 3913: 3908: 3904: 3892: 3891: 3889: 3887: 3885: 3883: 3880: 3879: 3864: 3861: 3847: 3842: 3825: 3819: 3816: 3802: 3797: 3785: 3782: 3775: 3772: 3757: 3753: 3752: 3737: 3734: 3720: 3715: 3698: 3692: 3689: 3675: 3670: 3658: 3647: 3643: 3642: 3627: 3624: 3610: 3605: 3588: 3577: 3572: 3560: 3557: 3550: 3547: 3532: 3528: 3527: 3525: 3523: 3521: 3519: 3516: 3515: 3498: 3495: 3492: 3481: 3476: 3459: 3456: 3453: 3442: 3437: 3425: 3414: 3410: 3409: 3406: 3403: 3400: 3397: 3396: 3182: 3179: 3154:Main article: 3151: 3148: 3114:Main article: 3111: 3108: 3057: 3056: 3047: 3034: 3031: 2975: 2972: 2969: 2968: 2963: 2957: 2956: 2949: 2923: 2920: 2868: 2865: 2862: 2861: 2859: 2857: 2851: 2850: 2843: 2836: 2832: 2831: 2828: 2825: 2807: 2795: 2792: 2791: 2790: 2785:is mapped to − 2779: 2776: 2775: 2774: 2753: 2719: 2694: 2690: 2665: 2638: 2634: 2603: 2597: 2581:symmetry group 2545: 2542: 2529: 2526: 2523: 2520: 2517: 2513: 2444: 2439: 2415: 2412: 2409: 2406: 2403: 2400: 2397: 2394: 2391: 2388: 2384: 2382: 2380: 2377: 2374: 2371: 2368: 2365: 2362: 2359: 2356: 2353: 2350: 2349: 2346: 2343: 2340: 2337: 2334: 2331: 2328: 2325: 2322: 2319: 2315: 2313: 2311: 2308: 2305: 2302: 2299: 2296: 2293: 2290: 2287: 2286: 2253: 2247: 2242: 2215: 2212: 2209: 2206: 2203: 2200: 2197: 2193: 2191: 2189: 2185: 2179: 2176: 2171: 2168: 2162: 2159: 2153: 2150: 2144: 2141: 2135: 2131: 2127: 2126: 2123: 2119: 2113: 2110: 2105: 2102: 2096: 2093: 2087: 2081: 2078: 2072: 2068: 2063: 2061: 2057: 2051: 2048: 2043: 2040: 2037: 2034: 2028: 2025: 2018: 2014: 2013: 1993: 1990: 1963: 1956: 1952: 1947: 1944: 1941: 1938: 1935: 1931: 1917: 1910: 1906: 1901: 1898: 1895: 1892: 1889: 1886: 1882: 1865: 1862: 1854:square degrees 1833: 1830: 1826: 1821: 1818: 1813: 1809: 1806: 1803: 1800: 1797: 1795: 1793: 1789: 1784: 1781: 1776: 1772: 1769: 1766: 1763: 1758: 1755: 1750: 1747: 1745: 1742: 1737: 1734: 1729: 1725: 1722: 1719: 1718: 1634: 1629: 1624: 1618: 1613: 1609: 1605: 1600: 1595: 1591: 1587: 1582: 1577: 1573: 1569: 1564: 1559: 1555: 1551: 1546: 1542: 1537: 1532: 1529: 1527: 1524: 1518: 1513: 1509: 1505: 1500: 1495: 1491: 1487: 1482: 1477: 1473: 1469: 1464: 1459: 1455: 1451: 1446: 1442: 1437: 1433: 1430: 1429: 1426: 1421: 1416: 1410: 1404: 1400: 1396: 1390: 1385: 1379: 1374: 1370: 1366: 1361: 1356: 1352: 1348: 1343: 1338: 1334: 1330: 1325: 1320: 1316: 1308: 1303: 1300: 1298: 1294: 1288: 1284: 1280: 1274: 1269: 1263: 1258: 1254: 1250: 1245: 1240: 1236: 1232: 1227: 1222: 1218: 1214: 1209: 1204: 1200: 1193: 1192: 1170: 1166: 1145: 1125: 1101: 1095: 1091: 1086: 1080: 1075: 1070: 1068: 1062: 1058: 1053: 1048: 1045: 1040: 1034: 1029: 1025: 1024: 1021: 1015: 1011: 1006: 1003: 998: 995: 990: 987: 983: 981: 978: 973: 969: 963: 960: 957: 956: 933: 928: 901: 896: 872: 849: 812: 807: 803: 799: 795: 790: 785: 781: 778: 775: 772: 769: 767: 764: 758: 755: 750: 746: 742: 739: 736: 735: 732: 727: 723: 719: 715: 709: 704: 700: 696: 693: 690: 687: 685: 682: 677: 674: 669: 665: 662: 659: 658: 647:dihedral angle 631: 626: 622: 618: 615: 607: 602: 596: 592: 586: 583: 578: 574: 568: 564: 558: 554: 548: 544: 537: 533: 528: 525: 520: 517: 497: 492: 488: 465: 460: 456: 452: 449: 444: 437: 433: 429: 425: 419: 415: 409: 405: 398: 394: 391: 388: 385: 365: 345: 323: 320: 202: 195: 194: 193: 185: 178: 177: 173: 166: 165: 164: 163: 162: 160: 157: 26: 9: 6: 4: 3: 2: 17729: 17718: 17715: 17713: 17710: 17708: 17705: 17703: 17700: 17698: 17695: 17693: 17690: 17688: 17685: 17684: 17682: 17671: 17667: 17663: 17658: 17655: 17651: 17648: 17646: 17639: 17632: 17626: 17624: 17620: 17617: 17615: 17611: 17607: 17603: 17600: 17598: 17594: 17591: 17589: 17585: 17581: 17580: 17577: 17575: 17573: 17570: 17568: 17564: 17561: 17559: 17556: 17554: 17551: 17550: 17547: 17545: 17543: 17540: 17538: 17534: 17531: 17529: 17526: 17524: 17521: 17520: 17517: 17515: 17508: 17501: 17495: 17493: 17490: 17488: 17484: 17481: 17479: 17476: 17474: 17471: 17470: 17467: 17465: 17458: 17451: 17445: 17443: 17440: 17438: 17434: 17431: 17429: 17426: 17424: 17421: 17420: 17417: 17415: 17408: 17402: 17400: 17397: 17395: 17391: 17388: 17386: 17383: 17381: 17378: 17377: 17374: 17372: 17370: 17367: 17365: 17361: 17358: 17356: 17353: 17351: 17348: 17347: 17344: 17340: 17337: 17335: 17332: 17330: 17329:Demitesseract 17327: 17325: 17321: 17318: 17316: 17313: 17311: 17308: 17307: 17304: 17300: 17297: 17295: 17293: 17290: 17288: 17284: 17281: 17279: 17276: 17274: 17271: 17270: 17267: 17264: 17262: 17259: 17257: 17254: 17252: 17249: 17247: 17244: 17242: 17239: 17238: 17235: 17229: 17226: 17222: 17215: 17211: 17204: 17200: 17195: 17191: 17186: 17182: 17177: 17175: 17173: 17169: 17159: 17155: 17153: 17151: 17147: 17143: 17141: 17139: 17135: 17131: 17129: 17126: 17125: 17120: 17116: 17108: 17103: 17101: 17096: 17094: 17089: 17088: 17085: 17075: 17069: 17063: 17060: 17058: 17055: 17053: 17050: 17048: 17045: 17043: 17040: 17038: 17035: 17033: 17030: 17028: 17025: 17023: 17020: 17018: 17015: 17013: 17010: 17009: 17007: 17003: 16993: 16990: 16988: 16985: 16984: 16982: 16978: 16972: 16969: 16967: 16964: 16963: 16960: 16957: 16953: 16947: 16946: 16942: 16940: 16939: 16935: 16934: 16932: 16928: 16922: 16919: 16917: 16914: 16912: 16909: 16907: 16904: 16902: 16899: 16897: 16894: 16892: 16889: 16887: 16884: 16882: 16879: 16877: 16874: 16872: 16869: 16867: 16864: 16862: 16859: 16858: 16856: 16849: 16844: 16838: 16835: 16833: 16830: 16828: 16825: 16823: 16820: 16818: 16815: 16813: 16810: 16808: 16805: 16803: 16800: 16798: 16795: 16793: 16790: 16788: 16785: 16783: 16782:cuboctahedron 16780: 16778: 16775: 16774: 16772: 16767: 16763: 16757: 16752: 16746: 16743: 16741: 16738: 16736: 16733: 16731: 16728: 16726: 16723: 16722: 16720: 16716: 16711: 16707: 16703: 16695: 16690: 16688: 16683: 16681: 16676: 16675: 16672: 16660: 16657: 16655: 16652: 16650: 16647: 16645: 16642: 16640: 16637: 16635: 16632: 16630: 16627: 16626: 16624: 16621: 16617: 16610: 16607: 16604: 16601: 16598: 16595: 16594: 16592: 16588: 16581: 16580:Johnson solid 16578: 16575: 16574:Catalan solid 16572: 16569: 16566: 16563: 16560: 16559: 16557: 16553: 16544: 16541: 16538: 16535: 16532: 16529: 16528: 16526: 16523: 16521: 16518: 16516: 16513: 16511: 16508: 16507: 16505: 16501: 16494: 16491: 16488: 16485: 16482: 16479: 16476: 16473: 16470: 16469:Hexoctahedron 16467: 16464: 16461: 16458: 16455: 16452: 16449: 16448: 16446: 16442: 16436: 16433: 16431: 16428: 16426: 16423: 16421: 16418: 16416: 16413: 16411: 16408: 16406: 16403: 16401: 16400:Tridecahedron 16398: 16396: 16393: 16391: 16390:Hendecahedron 16388: 16387: 16385: 16381: 16375: 16372: 16370: 16367: 16365: 16362: 16360: 16357: 16355: 16352: 16350: 16347: 16345: 16342: 16340: 16337: 16335: 16332: 16330: 16327: 16326: 16324: 16320: 16313: 16309: 16302: 16297: 16295: 16290: 16288: 16283: 16282: 16279: 16272: 16268: 16267: 16263: 16261: 16258: 16253: 16252: 16247: 16246:"Tetrahedron" 16244: 16239: 16238: 16227: 16221: 16218:. Routledge. 16217: 16212: 16208: 16204: 16203: 16195: 16190: 16186: 16182: 16178: 16174: 16169: 16164: 16160: 16156: 16152: 16147: 16143: 16139: 16134: 16130: 16129: 16124: 16120: 16113: 16112: 16106: 16102: 16096: 16092: 16091: 16085: 16081: 16077: 16073: 16069: 16065: 16061: 16057: 16053: 16048: 16044: 16038: 16034: 16030: 16029: 16023: 16019: 16015: 16014: 16009: 16005: 16001: 16000: 15995: 15991: 15987: 15983: 15978: 15974: 15968: 15964: 15960: 15955: 15954: 15939: 15938: 15933: 15930: 15923: 15915: 15911: 15907: 15903: 15899: 15896:(June 1903). 15895: 15889: 15873: 15867: 15859: 15855: 15851: 15845: 15837: 15835:9780177612992 15831: 15827: 15822: 15821: 15815: 15809: 15801: 15797: 15793: 15789: 15785: 15784: 15779: 15773: 15754: 15750: 15743: 15736: 15717: 15713: 15709: 15702: 15695: 15680: 15676: 15670: 15662: 15658: 15654: 15650: 15646: 15642: 15635: 15627: 15625:9780160876110 15621: 15617: 15616: 15608: 15601: 15600: 15595: 15590: 15582: 15578: 15575:, Solutions, 15571: 15570:"Problem 930" 15565: 15558: 15554: 15550: 15546: 15538: 15530: 15522:, p. 129 15521: 15520: 15512: 15496: 15492: 15485: 15478: 15475: 15473: 15466: 15464: 15462: 15460: 15452: 15447: 15439: 15435: 15431: 15427: 15423: 15419: 15412: 15404: 15400: 15396: 15392: 15388: 15384: 15383: 15378: 15372: 15364: 15360: 15353: 15342: 15335: 15327: 15321: 15310: 15309: 15301: 15292: 15284: 15280: 15276: 15272: 15267: 15262: 15258: 15254: 15253: 15245: 15238: 15231: 15226: 15219: 15214: 15208:, p. 11. 15207: 15202: 15200: 15192: 15187: 15180: 15176: 15171: 15164: 15160: 15155: 15147: 15143: 15138: 15133: 15129: 15125: 15121: 15114: 15107: 15103: 15098: 15091: 15086: 15075: 15070: 15063: 15058: 15056: 15046: 15041: 15037: 15033: 15029: 15025: 15019: 15012: 15007: 14999: 14993: 14986: 14981: 14972: 14969: 14966: 14963: 14962: 14958: 14951: 14947: 14942: 14935: 14934:"Tetrahedron" 14929: 14923:, Table I(i). 14922: 14917: 14915: 14913: 14905: 14901: 14900:Cromwell 1997 14896: 14889: 14885: 14880: 14873: 14868: 14860: 14859: 14851: 14842: 14841: 14836: 14835:"Tetrahedron" 14833: 14826: 14824: 14819: 14805: 14801: 14797: 14791: 14789: 14781: 14777: 14771: 14767: 14757: 14754: 14752: 14749: 14746: 14743: 14741: 14738: 14736: 14733: 14731: 14728: 14726: 14723: 14720: 14717: 14714: 14710: 14706: 14705:Demihypercube 14703: 14701: 14698: 14696: 14693: 14691: 14688: 14687: 14674: 14670: 14666: 14664: 14660: 14652: 14644: 14640: 14636: 14627: 14623: 14620: 14616: 14612: 14608: 14604: 14600: 14596: 14593: 14589: 14585: 14583: 14579: 14575: 14573: 14572:Automorphisms 14569: 14565: 14563: 14559: 14555: 14553: 14549: 14545: 14543: 14539: 14535: 14533: 14529: 14525: 14523: 14519: 14515: 14510: 14505: 14497: 14493: 14490: 14486: 14482: 14481:Marvin Minsky 14478: 14477: 14472: 14468: 14453: 14444: 14433: 14424: 14410: 14408: 14404: 14398: 14388: 14386: 14382: 14378: 14374: 14370: 14366: 14361: 14359: 14352: 14348: 14339: 14335: 14325: 14323: 14319: 14315: 14311: 14310:semiconductor 14307: 14302: 14300: 14296: 14293:If six equal 14290: 14286: 14276: 14274: 14270: 14266: 14261: 14259: 14254: 14252: 14247: 14232: 14228: 14210: 14209:central angle 14206: 14205: 14188: 14172: 14168: 14164: 14163:sp-hybridized 14160: 14154: 14147: 14142: 14135: 14130: 14121: 14119: 14109: 14107: 14097: 14095: 14091: 14087: 14083: 14079: 14075: 14071: 14067: 14063: 14059: 14056:of irregular 14055: 14051: 14047: 14038: 14024: 14022: 14018: 14013: 14011: 14006: 14004: 14000: 13996: 13995:mirror images 13992: 13988: 13984: 13980: 13976: 13972: 13964: 13958: 13953: 13950: 13944: 13939: 13936: 13930: 13925: 13922: 13921: 13915: 13912: 13909: 13906: 13904: 13901: 13899: 13896: 13894: 13891: 13889: 13886: 13884: 13881: 13879: 13876: 13874: 13871: 13869: 13866: 13865: 13861: 13857: 13854: 13850: 13847: 13843: 13840: 13836: 13833: 13829: 13826: 13822: 13819: 13815: 13812: 13808: 13805: 13801: 13798: 13794: 13791: 13787: 13784: 13780: 13779: 13772: 13767: 13764: 13760: 13754: 13749: 13747: 13742: 13740: 13735: 13734: 13731: 13727: 13722: 13719: 13717: 13707: 13704: 13701: 13698: 13696: 13693: 13691: 13688: 13686: 13683: 13681: 13678: 13676: 13673: 13671: 13668: 13666: 13663: 13661: 13658: 13657: 13653: 13649: 13646: 13642: 13639: 13635: 13632: 13628: 13625: 13621: 13618: 13614: 13611: 13607: 13604: 13600: 13597: 13593: 13590: 13586: 13583: 13579: 13576: 13572: 13571: 13564: 13558: 13554: 13548: 13543: 13541: 13536: 13534: 13529: 13528: 13525: 13521: 13516: 13513: 13511: 13507: 13503: 13494: 13491: 13489: 13486: 13484: 13481: 13479: 13476: 13474: 13471: 13469: 13466: 13464: 13461: 13459: 13456: 13455: 13451: 13447: 13444: 13440: 13437: 13433: 13430: 13426: 13423: 13419: 13416: 13412: 13409: 13405: 13402: 13398: 13397: 13392: 13389: 13386: 13384: 13381: 13379: 13376: 13374: 13371: 13369: 13366: 13364: 13361: 13359: 13356: 13354: 13351: 13350: 13320: 13291: 13262: 13233: 13204: 13175: 13146: 13117: 13116: 13112: 13108: 13105: 13101: 13098: 13094: 13091: 13087: 13084: 13080: 13077: 13073: 13070: 13066: 13063: 13059: 13058: 13054: 13051: 13048: 13044: 13041: 13037: 13034: 13032: 13028: 13018: 13015: 13012: 13009: 13006: 13003: 13000: 12998: 12995: 12990: 12986: 12983: 12980: 12977: 12973: 12970: 12966: 12963: 12959: 12956: 12952: 12949: 12945: 12942: 12939: 12935: 12932: 12929: 12925: 12922: 12918: 12915: 12911: 12908: 12904: 12901: 12897: 12894: 12891: 12887: 12884: 12881: 12879: 12876: 12874: 12871: 12869: 12866: 12864: 12861: 12858: 12852: 12849: 12848:Trapezohedron 12846: 12841: 12835: 12833: 12832: 12831:trapezohedron 12820: 12817: 12814: 12811: 12808: 12805: 12802: 12799: 12797: 12794: 12793: 12789: 12785: 12782: 12779: 12775: 12772: 12768: 12765: 12761: 12758: 12754: 12751: 12747: 12744: 12740: 12737: 12736: 12733: 12730: 12727: 12723: 12720: 12716: 12713: 12709: 12706: 12702: 12699: 12695: 12692: 12688: 12685: 12684: 12681: 12678: 12675: 12673: 12670: 12668: 12665: 12663: 12660: 12658: 12653: 12651: 12646: 12644: 12641: 12638: 12637: 12631: 12626: 12624: 12619: 12617: 12612: 12611: 12609: 12605: 12602: 12596: 12594: 12590: 12589: 12577: 12574: 12570: 12567: 12563: 12560: 12556: 12553: 12549: 12546: 12542: 12539: 12535: 12534: 12530: 12527: 12523: 12520: 12516: 12513: 12509: 12506: 12502: 12499: 12495: 12492: 12488: 12487: 12477: 12474: 12473: 12469: 12466: 12464: 12461: 12459: 12456: 12454: 12451: 12449: 12446: 12444: 12441: 12440: 12437: 12433: 12430: 12428: 12418: 12415: 12389: 12385: 12379: 12369: 12361: 12359: 12355: 12345: 12323: 12314: 12304: 12300: 12293: 12288: 12278: 12274: 12261: 12251: 12247: 12240: 12235: 12225: 12221: 12208: 12198: 12194: 12187: 12182: 12172: 12168: 12157: 12151: 12148: 12143: 12140: 12117: 12108: 12103: 12097: 12093: 12089: 12084: 12080: 12075: 12064: 12059: 12053: 12049: 12045: 12040: 12036: 12031: 12020: 12015: 12009: 12005: 12001: 11996: 11992: 11987: 11978: 11974: 11971: 11954: 11949: 11946: 11942: 11938: 11936: 11931: 11920: 11919: 11918: 11912: 11903: 11894: 11885: 11879: 11853: 11847: 11844: 11836: 11833: 11830: 11827: 11824: 11821: 11818: 11815: 11812: 11803: 11800: 11797: 11794: 11791: 11788: 11785: 11782: 11773: 11770: 11767: 11764: 11761: 11758: 11755: 11752: 11743: 11740: 11737: 11734: 11731: 11728: 11725: 11722: 11713: 11710: 11703: 11702: 11701: 11699: 11695: 11691: 11687: 11683: 11679: 11675: 11671: 11661: 11647: 11642: 11638: 11632: 11629: 11624: 11621: 11616: 11612: 11606: 11603: 11598: 11595: 11590: 11586: 11580: 11577: 11572: 11569: 11564: 11560: 11554: 11551: 11546: 11543: 11513: 11509: 11505: 11500: 11496: 11492: 11487: 11483: 11479: 11474: 11470: 11464: 11461: 11455: 11452: 11445: 11444: 11443: 11441: 11436: 11432: 11427: 11423: 11418: 11414: 11409: 11405: 11400: 11383: 11376: 11372: 11368: 11363: 11356: 11351: 11347: 11343: 11338: 11331: 11326: 11322: 11318: 11313: 11306: 11301: 11297: 11293: 11288: 11281: 11276: 11272: 11268: 11259: 11258: 11257: 11255: 11250: 11246: 11242: 11238: 11214: 11208: 11205: 11202: 11199: 11196: 11193: 11190: 11187: 11184: 11181: 11178: 11172: 11169: 11166: 11163: 11160: 11157: 11154: 11151: 11148: 11145: 11142: 11139: 11136: 11129: 11128: 11127: 11125: 11121: 11117: 11113: 11109: 11105: 11101: 11097: 11093: 11089: 11086:For vertices 11070: 11067: 11064: 11061: 11050: 11046: 11043: 11040: 11037: 11026: 11022: 11019: 11016: 11013: 11002: 10998: 10995: 10992: 10989: 10978: 10974: 10971: 10968: 10961: 10960: 10959: 10954: 10947: 10940: 10933: 10929: 10925: 10921: 10917: 10913: 10909: 10899: 10881: 10878: 10874: 10870: 10867: 10862: 10852: 10844: 10839: 10836: 10832: 10828: 10825: 10820: 10810: 10802: 10797: 10794: 10790: 10786: 10783: 10778: 10768: 10757: 10754: 10749: 10744: 10736: 10731: 10726: 10718: 10713: 10708: 10700: 10695: 10690: 10677: 10659: 10655: 10649: 10645: 10622: 10619: 10615: 10592: 10588: 10565: 10538: 10534: 10511: 10507: 10484: 10480: 10457: 10453: 10442: 10432: 10429: 10423: 10420: 10415: 10397: 10394: 10391: 10388: 10382: 10379: 10376: 10373: 10370: 10367: 10361: 10358: 10355: 10352: 10349: 10346: 10340: 10337: 10334: 10331: 10328: 10325: 10319: 10316: 10313: 10310: 10307: 10304: 10298: 10295: 10292: 10289: 10286: 10283: 10277: 10274: 10267: 10266: 10265: 10263: 10259: 10255: 10251: 10247: 10241: 10236: 10234: 10224: 10222: 10217: 10213: 10211: 10207: 10203: 10198: 10196: 10192: 10188: 10184: 10179: 10177: 10172: 10168: 10166: 10162: 10158: 10148: 10146: 10142: 10138: 10134: 10130: 10126: 10122: 10118: 10114: 10110: 10106: 10102: 10098: 10094: 10090: 10086: 10082: 10077: 10075: 10071: 10067: 10044: 10041: 10036: 10030: 10027: 10016: 10012: 10004: 10001: 9990: 9986: 9978: 9975: 9964: 9960: 9952: 9949: 9936: 9932: 9924: 9921: 9916: 9913: 9902: 9898: 9890: 9887: 9876: 9872: 9864: 9861: 9848: 9844: 9836: 9833: 9822: 9818: 9810: 9807: 9802: 9799: 9788: 9784: 9776: 9773: 9760: 9756: 9748: 9745: 9734: 9730: 9722: 9719: 9708: 9704: 9696: 9693: 9688: 9685: 9679: 9670: 9669: 9668: 9665: 9662: 9659: 9655: 9651: 9646: 9644: 9640: 9636: 9631: 9629: 9625: 9621: 9617: 9613: 9609: 9605: 9601: 9596: 9592: 9590: 9586: 9582: 9581:Gaspard Monge 9578: 9576: 9565: 9552: 9547: 9518: 9502: 9496: 9493: 9473: 9465: 9444: 9419: 9399: 9391: 9386: 9384: 9380: 9376: 9372: 9367: 9365: 9360: 9343: 9337: 9334: 9331: 9328: 9325: 9315: 9312: 9309: 9306: 9303: 9297: 9294: 9288: 9282: 9279: 9276: 9273: 9270: 9261: 9258: 9255: 9252: 9249: 9243: 9240: 9233: 9227: 9224: 9221: 9218: 9215: 9206: 9203: 9200: 9197: 9194: 9188: 9185: 9179: 9173: 9170: 9167: 9164: 9161: 9152: 9149: 9146: 9143: 9140: 9134: 9131: 9124: 9118: 9115: 9112: 9109: 9106: 9097: 9094: 9091: 9088: 9085: 9079: 9076: 9070: 9064: 9061: 9058: 9055: 9052: 9043: 9040: 9037: 9034: 9031: 9025: 9022: 8994: 8989: 8986: 8983: 8978: 8975: 8969: 8964: 8961: 8958: 8953: 8950: 8943: 8938: 8935: 8932: 8927: 8924: 8918: 8913: 8910: 8907: 8902: 8899: 8872: 8868: 8864: 8860: 8852: 8849: 8846: 8843: 8840: 8837: 8834: 8824: 8821: 8818: 8815: 8812: 8809: 8806: 8796: 8793: 8790: 8787: 8784: 8781: 8778: 8768: 8765: 8762: 8759: 8756: 8753: 8750: 8747: 8737: 8734: 8714: 8694: 8674: 8654: 8634: 8614: 8594: 8574: 8554: 8534: 8514: 8494: 8481: 8477: 8461: 8457: 8452: 8448: 8444: 8440: 8436: 8431: 8427: 8423: 8419: 8415: 8410: 8406: 8402: 8398: 8394: 8391: 8387: 8383: 8380: 8376: 8372: 8369: 8366: 8363: 8360: 8353: 8349: 8346: 8343: 8337: 8334: 8310: 8305: 8301: 8297: 8292: 8288: 8284: 8279: 8275: 8271: 8269: 8264: 8257: 8252: 8248: 8244: 8239: 8235: 8231: 8226: 8222: 8218: 8216: 8211: 8204: 8199: 8195: 8191: 8186: 8182: 8178: 8173: 8169: 8165: 8163: 8158: 8132: 8128: 8125: 8122: 8119: 8114: 8110: 8104: 8100: 8096: 8091: 8087: 8081: 8077: 8073: 8068: 8064: 8058: 8054: 8050: 8045: 8041: 8035: 8031: 8025: 8021: 8017: 8011: 8008: 7988: 7968: 7948: 7928: 7908: 7888: 7868: 7859: 7857: 7853: 7849: 7844: 7835: 7831: 7827: 7823: 7815: 7811: 7789: 7783: 7776: 7771: 7767: 7759: 7754: 7750: 7742: 7737: 7733: 7727: 7718: 7713: 7709: 7703: 7696: 7691: 7687: 7679: 7674: 7670: 7664: 7655: 7650: 7646: 7638: 7633: 7629: 7623: 7616: 7611: 7607: 7601: 7592: 7587: 7583: 7575: 7570: 7566: 7558: 7553: 7549: 7543: 7538: 7531: 7526: 7521: 7516: 7511: 7505: 7500: 7495: 7491: 7487: 7484: 7477: 7476: 7475: 7473: 7454: 7449: 7444: 7437: 7432: 7427: 7422: 7413: 7409: 7401: 7397: 7389: 7385: 7377: 7373: 7363: 7359: 7351: 7347: 7339: 7335: 7327: 7323: 7313: 7309: 7301: 7297: 7289: 7285: 7277: 7273: 7265: 7257: 7253: 7250: 7247: 7244: 7237: 7236: 7235: 7233: 7228: 7226: 7222: 7218: 7214: 7210: 7206: 7202: 7198: 7194: 7190: 7186: 7182: 7178: 7174: 7154: 7148: 7144: 7139: 7135: 7131: 7127: 7123: 7118: 7114: 7110: 7106: 7102: 7097: 7093: 7089: 7085: 7081: 7078: 7074: 7070: 7067: 7063: 7059: 7056: 7053: 7050: 7047: 7040: 7036: 7033: 7030: 7024: 7021: 7014: 7013: 7012: 6977: 6974: 6933: 6930: 6889: 6886: 6856: 6852: 6848: 6845: 6842: 6839: 6836: 6828: 6816: 6812: 6808: 6805: 6802: 6799: 6796: 6788: 6776: 6772: 6768: 6765: 6762: 6759: 6756: 6748: 6737: 6707: 6682: 6667: 6650: 6621: 6604: 6589: 6564: 6559: 6554: 6550: 6546: 6543: 6536: 6535: 6534: 6506: 6498: 6494: 6490: 6485: 6481: 6477: 6472: 6468: 6461: 6449: 6441: 6437: 6433: 6428: 6424: 6420: 6415: 6411: 6404: 6392: 6384: 6380: 6376: 6371: 6367: 6363: 6358: 6354: 6347: 6336: 6269: 6266: 6263: 6260: 6199: 6196: 6193: 6190: 6183: 6182: 6181: 6178: 6160: 6156: 6132: 6124: 6116: 6108: 6100: 6084: 6081: 6072: 6052: 6044: 6040: 6036: 6031: 6027: 6023: 6018: 6014: 6007: 6005: 5991: 5983: 5979: 5975: 5970: 5966: 5962: 5957: 5953: 5946: 5944: 5930: 5922: 5918: 5914: 5909: 5905: 5901: 5896: 5892: 5885: 5883: 5869: 5861: 5857: 5853: 5848: 5844: 5840: 5835: 5831: 5824: 5822: 5802: 5787: 5779: 5763: 5743: 5740: 5737: 5732: 5729: 5724: 5721: 5702: 5686: 5682: 5678: 5666: 5663: 5658: 5656: 5640: 5637: 5635: 5630: 5627: 5626: 5623: 5618: 5614: 5607: 5600: 5596: 5588: 5582: 5574: 5568: 5563: 5560: 5555: 5548: 5545: 5544: 5537: 5534: 5527: 5520: 5512: 5506: 5500: 5496: 5491: 5487: 5484: 5482: 5477: 5474: 5473: 5470: 5437: 5430: 5423: 5420: 5413: 5405: 5399: 5395: 5389: 5384: 5381: 5371: 5368: 5367: 5364: 5331: 5323: 5315: 5309: 5305: 5301: 5297: 5293: 5290: 5288: 5282: 5281: 5278: 5276: 5275:trivial group 5265: 5255: 5251: 5248: 5246: 5241: 5233: 5225: 5222: 5221: 5214: 5210: 5203: 5197: 5189: 5181: 5175: 5170: 5167: 5157: 5154: 5153: 5146: 5142: 5135: 5128: 5124: 5116: 5108: 5102: 5097: 5094: 5092: 5085: 5082: 5081: 5077: 5046: 5039: 5035: 5028: 5022: 5014: 5006: 5003: 5000: 4998: 4995: 4993: 4990: 4988: 4985: 4984: 4981: 4977: 4962: 4959: 4949: 4939: 4937: 4933: 4928: 4923: 4921: 4917: 4913: 4909: 4904: 4902: 4898: 4894: 4890: 4881: 4872: 4870: 4866: 4862: 4858: 4853: 4851: 4847: 4843: 4839: 4829: 4810: 4807: 4777: 4774: 4744: 4741: 4711: 4708: 4678: 4675: 4645: 4642: 4612: 4609: 4579: 4576: 4550: 4541: 4520: 4517: 4487: 4484: 4458: 4449: 4428: 4425: 4395: 4392: 4362: 4359: 4346: 4325: 4322: 4296: 4270: 4267: 4229: 4225: 4222:arc sec  4175: 4172: 4170: 4168: 4166: 4164: 4163: 4139: 4136: 4129: 4126: 4099: 4095: 4091: 4086: 4083: 4073: 4049: 4046: 4039: 4036: 4009: 4005: 4001: 3996: 3993: 3983: 3959: 3956: 3949: 3946: 3919: 3915: 3911: 3906: 3903: 3893: 3890: 3888: 3886: 3884: 3882: 3881: 3862: 3859: 3823: 3817: 3814: 3783: 3780: 3773: 3770: 3754: 3735: 3732: 3696: 3690: 3687: 3656: 3644: 3625: 3622: 3586: 3558: 3555: 3548: 3545: 3529: 3526: 3524: 3522: 3520: 3518: 3517: 3496: 3493: 3490: 3457: 3454: 3451: 3423: 3411: 3398: 3393: 3390: 3332: 3327: 3325: 3321: 3240: 3234: 3232: 3228: 3223: 3219: 3215: 3211: 3206: 3204: 3200: 3196: 3195:3-orthoscheme 3187: 3178: 3175: 3167: 3162: 3157: 3147: 3145: 3141: 3139: 3135: 3131: 3122: 3117: 3107: 3105: 3101: 3096: 3094: 3090: 3086: 3082: 3077: 3075: 3071: 3067: 3066:perpendicular 3062: 3052: 3048: 3043: 3039: 3038: 3030: 3028: 3024: 3020: 3016: 3012: 3008: 3003: 3001: 2997: 2989: 2985: 2980: 2967: 2962: 2959: 2958: 2954: 2950: 2947: 2943: 2939: 2937: 2933: 2929: 2919: 2917: 2908: 2904: 2902: 2898: 2894: 2890: 2882: 2878: 2873: 2860: 2858: 2853: 2848: 2844: 2841: 2837: 2834: 2829: 2826: 2823: 2822: 2819: 2814: 2812: 2811:Coxeter plane 2805: 2801: 2788: 2784: 2780: 2777: 2771: 2767: 2763: 2757:3 ((1 2)(3 4) 2754: 2741: 2737: 2733: 2720: 2717: 2716: 2714: 2710: 2692: 2688: 2680: 2654: 2653: 2652: 2636: 2632: 2624: 2620: 2586: 2582: 2573: 2569: 2567: 2563: 2559: 2550: 2541: 2524: 2521: 2518: 2503: 2472: 2468: 2464: 2460: 2442: 2437: 2413: 2407: 2404: 2401: 2398: 2395: 2392: 2389: 2383: 2378: 2372: 2369: 2366: 2363: 2360: 2357: 2354: 2344: 2338: 2335: 2332: 2329: 2326: 2323: 2320: 2314: 2309: 2303: 2300: 2297: 2294: 2291: 2276: 2272: 2267: 2251: 2245: 2240: 2210: 2207: 2204: 2201: 2198: 2192: 2187: 2183: 2177: 2174: 2169: 2166: 2160: 2157: 2151: 2148: 2142: 2139: 2133: 2129: 2121: 2117: 2111: 2108: 2103: 2100: 2094: 2091: 2085: 2079: 2076: 2070: 2066: 2059: 2055: 2049: 2046: 2041: 2038: 2035: 2032: 2026: 2023: 2016: 1991: 1988: 1980: 1975: 1961: 1954: 1950: 1945: 1942: 1939: 1936: 1933: 1929: 1915: 1908: 1904: 1899: 1896: 1893: 1890: 1887: 1884: 1880: 1871: 1861: 1859: 1856:, or 0.04387 1855: 1851: 1831: 1828: 1824: 1819: 1816: 1811: 1807: 1804: 1801: 1798: 1796: 1787: 1782: 1779: 1774: 1770: 1767: 1764: 1761: 1756: 1753: 1748: 1746: 1740: 1735: 1732: 1727: 1723: 1720: 1708: 1703: 1701: 1696: 1692: 1688: 1684: 1680: 1676: 1672: 1654: 1649: 1632: 1627: 1622: 1616: 1611: 1607: 1603: 1598: 1593: 1589: 1585: 1580: 1575: 1571: 1567: 1562: 1557: 1553: 1549: 1544: 1540: 1535: 1530: 1528: 1522: 1516: 1511: 1507: 1503: 1498: 1493: 1489: 1485: 1480: 1475: 1471: 1467: 1462: 1457: 1453: 1449: 1444: 1440: 1435: 1431: 1424: 1419: 1414: 1408: 1402: 1398: 1394: 1388: 1383: 1377: 1372: 1368: 1364: 1359: 1354: 1350: 1346: 1341: 1336: 1332: 1328: 1323: 1318: 1314: 1306: 1301: 1299: 1292: 1286: 1282: 1278: 1272: 1267: 1261: 1256: 1252: 1248: 1243: 1238: 1234: 1230: 1225: 1220: 1216: 1212: 1207: 1202: 1198: 1168: 1164: 1143: 1123: 1099: 1093: 1089: 1084: 1073: 1066: 1060: 1056: 1051: 1046: 1043: 1038: 1027: 1019: 1013: 1009: 1004: 1001: 996: 993: 988: 985: 979: 976: 971: 967: 961: 958: 926: 918: 894: 886: 870: 863: 847: 840: 831: 827: 810: 805: 801: 797: 793: 788: 783: 779: 776: 773: 770: 768: 762: 756: 753: 748: 744: 740: 737: 730: 725: 721: 717: 713: 707: 702: 698: 694: 691: 688: 686: 680: 675: 672: 667: 663: 660: 648: 643: 629: 624: 620: 616: 613: 605: 600: 594: 590: 584: 581: 576: 572: 566: 562: 556: 552: 546: 542: 535: 531: 526: 523: 518: 515: 495: 490: 486: 463: 458: 454: 450: 447: 442: 435: 431: 427: 423: 417: 413: 407: 403: 396: 392: 389: 386: 383: 363: 343: 329: 319: 317: 313: 309: 305: 301: 296: 294: 290: 286: 282: 277: 275: 271: 267: 263: 259: 255: 250: 248: 244: 240: 236: 231: 229: 225: 221: 217: 206: 199: 189: 182: 170: 156: 154: 150: 146: 141: 139: 135: 130: 128: 124: 120: 115: 113: 109: 106: 102: 97: 95: 91: 87: 83: 79: 75: 71: 67: 59: 55: 50: 46: 44: 39: 38: 33: 19: 17649: 17618: 17609: 17601: 17592: 17583: 17563:10-orthoplex 17299:Dodecahedron 17291: 17277: 17220: 17209: 17198: 17189: 17180: 17171: 17167: 17157: 17149: 17145: 17137: 17133: 17073: 16992:trapezohedra 16943: 16936: 16740:dodecahedron 16493:Apeirohedron 16444:>20 faces 16395:Dodecahedron 16343: 16271:kaleidocycle 16265: 16249: 16215: 16206: 16200: 16158: 16154: 16141: 16137: 16127: 16110: 16089: 16055: 16051: 16027: 16012: 15998: 15985: 15981: 15958: 15950:Bibliography 15935: 15922: 15905: 15901: 15888: 15876:. Retrieved 15866: 15857: 15844: 15819: 15808: 15782: 15772: 15760:. Retrieved 15753:the original 15748: 15735: 15725:15 September 15723:. Retrieved 15716:the original 15711: 15707: 15694: 15682:. Retrieved 15678: 15669: 15644: 15640: 15634: 15614: 15607: 15597: 15589: 15580: 15576: 15564: 15548: 15544: 15536: 15529: 15524:( Art. 163 ) 15518: 15511: 15499:. Retrieved 15494: 15484: 15469: 15446: 15421: 15417: 15411: 15386: 15380: 15371: 15362: 15358: 15352: 15334: 15307: 15300: 15291: 15256: 15250: 15237: 15225: 15218:Bottema 1969 15213: 15186: 15170: 15154: 15127: 15123: 15113: 15105: 15102:Coxeter 1973 15097: 15090:Coxeter 1973 15085: 15074:Coxeter 1973 15069: 15062:Coxeter 1973 15035: 15031: 15018: 15006: 14992: 14980: 14971:Brittin 1945 14965:Coxeter 1948 14957: 14941: 14928: 14921:Coxeter 1948 14895: 14879: 14867: 14857: 14850: 14838: 14804:golden ratio 14799: 14796:Coxeter 1973 14770: 14712: 14632: 14619:planar graph 14494: 14474: 14465: 14400: 14377:Rubik's Cube 14362: 14355: 14351:4-sided dice 14337: 14303: 14292: 14273:tetrahedrane 14268: 14262: 14255: 14248: 14229: 14202: 14156: 14115: 14103: 14078:aerodynamics 14050:approximated 14043: 14027:Applications 14014: 14007: 13991:right-handed 13983:dodecahedron 13968: 13872: 13729: 13725: 13713: 13664: 13523: 13519: 13505: 13499: 13477: 13457: 13372: 13352: 13024: 12982:Plane tiling 12856: 12839: 12828: 12826: 12654:(Tetragonal) 12603: 12585: 12583: 12481:Equilateral 12447: 12424: 12416: 12381: 12367: 12351: 12343: 11910: 11901: 11892: 11883: 11877: 11873: 11870:Circumcenter 11697: 11693: 11689: 11685: 11681: 11677: 11673: 11669: 11667: 11664:Circumradius 11534: 11442:is given by 11439: 11434: 11430: 11425: 11421: 11416: 11412: 11407: 11403: 11401: 11398: 11253: 11248: 11244: 11236: 11234: 11123: 11119: 11115: 11111: 11107: 11103: 11099: 11095: 11091: 11087: 11085: 10952: 10945: 10938: 10931: 10927: 10923: 10919: 10915: 10911: 10907: 10905: 10444: 10424: 10418: 10416: 10413: 10261: 10257: 10253: 10249: 10246:law of sines 10243: 10230: 10218: 10214: 10199: 10191:rhombohedron 10180: 10173: 10169: 10154: 10144: 10140: 10136: 10132: 10128: 10124: 10120: 10116: 10112: 10104: 10100: 10096: 10088: 10078: 10073: 10069: 10062: 10060: 9666: 9663: 9657: 9653: 9649: 9647: 9643:Euler points 9642: 9638: 9632: 9623: 9615: 9607: 9603: 9597: 9593: 9584: 9579: 9571: 9486:is given by 9387: 9368: 9361: 8486: 7860: 7839: 7833: 7829: 7825: 7821: 7813: 7809: 7806: 7469: 7231: 7229: 7224: 7220: 7216: 7212: 7208: 7204: 7203:. The angle 7200: 7196: 7192: 7188: 7187:. The angle 7184: 7180: 7176: 7172: 7170: 6878: 6532: 6179: 5803: 5713: 5667: 5661: 5659: 5654: 5651: 5628: 5616: 5613:cyclic group 5605: 5603: 5598: 5594: 5553: 5546: 5535: 5525: 5518: 5475: 5435: 5428: 5421: 5416: 5411: 5369: 5329: 5326: 5321: 5272: 5239: 5231: 5223: 5212: 5209:cyclic group 5201: 5195: 5155: 5144: 5133: 5126: 5122: 5090: 5083: 5037: 5026: 5020: 4974:Description 4945: 4924: 4919: 4915: 4908:kaleidoscope 4905: 4886: 4854: 4852:to a cube.) 4842:mirror image 4837: 4835: 4447: 4344: 4254: 3328: 3319: 3235: 3230: 3226: 3216:that is the 3207: 3194: 3192: 3181:Orthoschemes 3171: 3142: 3138:right angles 3133: 3127: 3099: 3097: 3080: 3078: 3073: 3063: 3060: 3004: 2993: 2925: 2913: 2888: 2886: 2876: 2827:Face/vertex 2824:Centered by 2799: 2798:The regular 2797: 2786: 2782: 2769: 2765: 2761: 2739: 2735: 2731: 2578: 2555: 2268: 1976: 1867: 1704: 1694: 1690: 1682: 1670: 1655:of a face (2 1650: 839:circumsphere 836: 644: 335: 297: 278: 265: 251: 232: 215: 213: 145:circumsphere 142: 131: 116: 111: 98: 73: 70:tetrahedrons 69: 65: 57: 51: 49: 42: 36: 32:tetrahedroid 17572:10-demicube 17533:9-orthoplex 17483:8-orthoplex 17433:7-orthoplex 17390:6-orthoplex 17360:5-orthoplex 17315:Pentachoron 17303:Icosahedron 17278:Tetrahedron 16762:semiregular 16745:icosahedron 16725:tetrahedron 16435:Icosahedron 16383:11–20 faces 16369:Enneahedron 16359:Heptahedron 16349:Pentahedron 16344:Tetrahedron 15878:20 February 15762:11 November 15175:Fekete 1985 15011:Kepler 1619 14967:Table I(i). 14756:Orthoscheme 14719:Pentachoron 14651:wheel graph 14595:Hamiltonian 14385:Pyramorphix 14369:4-sided die 14365:roleplaying 14334:Color space 14328:Color space 14289:Electronics 14285:Electricity 14249:Quaternary 14204:Tetrahedron 14146:dot product 14106:spaceframes 13987:left-handed 12857:Tetrahedron 12467:Heptagonal 11106:, and feet 9648:The center 9585:Monge point 6071:determinant 5780:' area and 5410:Four equal 5320:Four equal 5300:Disphenoids 5123:equilateral 5021:equilateral 4969:equivalence 4954:, ), and (S 3218:convex hull 3210:orthoscheme 3136:vertex are 2986:within the 2800:tetrahedron 2467:alternating 1979:unit sphere 1707:solid angle 322:Measurement 228:deltahedron 88:, and four 58:tetrahedron 43:Tetrahedron 17717:Tetrahedra 17687:Deltahedra 17681:Categories 17558:10-simplex 17542:9-demicube 17492:8-demicube 17442:7-demicube 17399:6-demicube 17369:5-demicube 17283:Octahedron 17057:prismatoid 16987:bipyramids 16971:antiprisms 16945:hosohedron 16735:octahedron 16620:prismatoid 16605:(infinite) 16374:Decahedron 16364:Octahedron 16354:Hexahedron 16329:Monohedron 16322:1–10 faces 16209:: 227–232. 15647:(3): 145. 15206:Kahan 2012 15177:, p.  15161:, p.  15130:: 128631. 14948:, p.  14902:, p.  14886:, p.  14872:Cundy 1952 14814:References 14591:Properties 14173:molecule ( 14058:tetrahedra 13762:Spherical 13556:Spherical 13493:V3.3.3.3.3 13031:octahedron 12893:Polyhedron 12838:Family of 12647:(Trigonal) 12608:antiprisms 12599:Family of 12484:Isosceles 12458:Pentagonal 12448:Triangular 10264:, we have 10206:disphenoid 9628:Euler line 9624:Euler line 9612:concurrent 9390:skew lines 5194:Two equal 4927:honeycombs 4869:octahedron 3440:109°28′16″ 3203:disphenoid 3174:disphenoid 3156:Disphenoid 3150:Disphenoid 3093:concurrent 2854:Projective 2723:8 ((1 2 3) 2619:isomorphic 2562:symmetries 1850:steradians 1671:horizontal 300:tessellate 281:truncation 274:rectifying 270:octahedron 78:polyhedron 66:tetrahedra 37:Tetraedron 17606:orthoplex 17528:9-simplex 17478:8-simplex 17428:7-simplex 17385:6-simplex 17355:5-simplex 17324:Tesseract 17052:birotunda 17042:bifrustum 16807:snub cube 16702:polyhedra 16634:antiprism 16339:Trihedron 16308:Polyhedra 16251:MathWorld 16177:1019-8385 16144:(1): 1–6. 16080:250435684 16028:Polyhedra 15937:MathWorld 15320:cite book 15266:1304.0179 15146:0096-3003 14985:Park 2016 14840:MathWorld 14603:symmetric 14295:resistors 14124:Chemistry 14118:airfields 13766:Euclidean 13052:, (*332) 13019:V∞.3.3.3 13013:V6.3.3.3 13010:V5.3.3.3 13007:V4.3.3.3 13004:V3.3.3.3 13001:V2.3.3.3 12588:antiprism 12475:Improper 12463:Hexagonal 12311:‖ 12297:‖ 12294:− 12285:‖ 12271:‖ 12258:‖ 12244:‖ 12241:− 12232:‖ 12218:‖ 12205:‖ 12191:‖ 12188:− 12179:‖ 12165:‖ 12090:− 12046:− 12002:− 11947:− 11813:− 11789:− 11768:− 11364:≤ 11170:≥ 11062:≥ 11047:⋅ 11023:⋅ 10999:⋅ 10975:⋅ 10875:θ 10871:⁡ 10859:Δ 10849:Δ 10833:θ 10829:⁡ 10817:Δ 10807:Δ 10791:θ 10787:⁡ 10775:Δ 10765:Δ 10755:− 10741:Δ 10723:Δ 10705:Δ 10687:Δ 10616:θ 10562:Δ 10386:∠ 10383:⁡ 10377:⋅ 10365:∠ 10362:⁡ 10356:⋅ 10344:∠ 10341:⁡ 10323:∠ 10320:⁡ 10314:⋅ 10302:∠ 10299:⁡ 10293:⋅ 10281:∠ 10278:⁡ 10187:Aristotle 10028:− 10013:α 10005:⁡ 9987:α 9979:⁡ 9961:α 9953:⁡ 9933:α 9925:⁡ 9914:− 9899:α 9891:⁡ 9873:α 9865:⁡ 9845:α 9837:⁡ 9819:α 9811:⁡ 9800:− 9785:α 9777:⁡ 9757:α 9749:⁡ 9731:α 9723:⁡ 9705:α 9697:⁡ 9686:− 9529:− 9519:× 9445:− 9329:− 9307:− 9253:− 9219:− 9198:− 9144:− 9110:− 9089:− 9035:− 8850:− 8816:− 8782:− 8748:− 8707:opposite 8667:opposite 8627:opposite 8462:γ 8458:⁡ 8445:− 8441:β 8437:⁡ 8424:− 8420:α 8416:⁡ 8403:− 8399:γ 8395:⁡ 8388:β 8384:⁡ 8377:α 8373:⁡ 8298:− 8245:− 8192:− 8097:− 8074:− 8051:− 7488:⋅ 7248:⋅ 7234:= 0 then 7149:γ 7145:⁡ 7132:− 7128:β 7124:⁡ 7111:− 7107:α 7103:⁡ 7090:− 7086:γ 7082:⁡ 7075:β 7071:⁡ 7064:α 7060:⁡ 6853:β 6849:⁡ 6829:⋅ 6813:α 6809:⁡ 6789:⋅ 6773:γ 6769:⁡ 6749:⋅ 6683:⋅ 6668:⋅ 6651:⋅ 6622:⋅ 6605:⋅ 6590:⋅ 6547:⋅ 6264:⋅ 6194:⋅ 6133:− 6117:− 6101:− 5601:triangles 5599:isosceles 5521:triangles 5519:isosceles 5414:triangles 5324:triangles 5322:isosceles 5127:isosceles 5023:triangles 4205:35°15′52″ 4186:𝜿 4137:≈ 4047:≈ 3957:≈ 3860:π 3828:𝜿 3824:− 3815:π 3781:≈ 3733:π 3701:𝜿 3697:− 3688:π 3623:π 3591:𝜿 3575:70°31′44″ 3556:≈ 3501:𝟁 3494:− 3491:π 3479:70°31′44″ 3462:𝜿 3455:− 3452:π 3408:dihedral 3089:incenters 2936:conformal 2893:rectangle 2856:symmetry 2583:known as 2399:− 2390:− 2370:− 2355:− 2336:− 2327:− 2170:− 2152:− 2134:− 2104:− 2071:− 2042:− 1940:± 1900:− 1885:± 1852:, 1809.8 1832:π 1829:− 1808:⁡ 1771:⁡ 1762:− 1754:π 1724:⁡ 885:midsphere 806:∘ 798:≈ 780:⁡ 749:− 741:⁡ 726:∘ 718:≈ 695:⁡ 664:⁡ 614:≈ 567:⋅ 532:⋅ 448:≈ 393:⋅ 132:Like all 112:3-simplex 105:Euclidean 45:(journal) 17660:Topics: 17623:demicube 17588:polytope 17582:Uniform 17343:600-cell 17339:120-cell 17292:Demicube 17266:Pentagon 17246:Triangle 17032:bicupola 17012:pyramids 16938:dihedron 16334:Dihedron 16125:(1619). 16010:(1973). 15996:(1948). 15816:(1965). 15780:(1875). 15501:7 August 15451:Lee 1997 15438:15558830 15026:(1989). 14684:See also 14635:skeleton 14552:Diameter 14522:Vertices 14489:HAL 9000 14471:monolith 14381:Pyraminx 14322:crystals 14312:used in 14299:soldered 14187:ammonium 14185:) or an 14134:ammonium 14116:At some 14112:Aviation 13975:compound 13907:{12i,3} 13773:Paraco. 13565:Paraco. 13559:Euclid. 13483:V3.4.3.4 13468:V3.3.3.3 13055:, (332) 13047:Symmetry 12829:digonal 12821:∞.3.3.3 12815:7.3.3.3 12812:6.3.3.3 12809:5.3.3.3 12806:4.3.3.3 12803:3.3.3.3 12800:2.3.3.3 12586:digonal 12478:Regular 12358:Centroid 12348:Centroid 11239:and the 11231:Inradius 10607:and let 10204:and the 9616:centroid 9608:bimedian 9600:centroid 8727:. Then, 7215:, while 6997:‖ 6983:‖ 6953:‖ 6939:‖ 6909:‖ 6895:‖ 6307:‖ 6275:‖ 6233:‖ 6205:‖ 4980:Symmetry 4971:diagram 3800:54°44′8″ 3673:54°44′8″ 3027:3-sphere 3023:600-cell 2988:600-cell 2759:, etc.; 2725:, etc.; 2544:Symmetry 2463:demicube 1687:centroid 917:exsphere 862:insphere 314:and the 293:kleetope 258:compound 149:insphere 127:triangle 90:vertices 54:geometry 17597:simplex 17567:10-cube 17334:24-cell 17320:16-cell 17261:Hexagon 17115:regular 17074:italics 17062:scutoid 17047:rotunda 17037:frustum 16766:uniform 16715:regular 16700:Convex 16654:pyramid 16639:frustum 16185:2154824 16072:3608204 15988:: 6–10. 15800:3571917 15788:Bibcode 15649:Bibcode 15403:2689983 15283:3647851 14709:simplex 14700:Caltrop 14599:regular 14391:Geology 14318:valence 14306:silicon 14225:⁠ 14213:⁠ 14171:methane 13979:origami 13973:. This 13916:{3i,3} 13913:{6i,3} 13910:{9i,3} 13388:sr{3,3} 13383:tr{3,3} 13378:rr{3,3} 12606:-gonal 12601:uniform 12443:Digonal 12427:pyramid 11672:. Let 11241:inradii 10958:. Then 10208:of the 10157:simplex 9364:bisects 6175:⁠ 6163:⁠ 5776:is the 5595:scalene 5412:scalene 5196:scalene 5078:{3,3}. 4863:). The 3320:smaller 3313:√ 3250:√ 3243:√ 3214:simplex 3085:cevians 3019:16-cell 2750:⁠ 2727:⁠ 2621:to the 1685:is the 1664:√ 1657:√ 802:109.471 153:tangent 123:polygon 119:pyramid 108:simplex 76:, is a 17537:9-cube 17487:8-cube 17437:7-cube 17394:6-cube 17364:5-cube 17251:Square 17128:Family 17027:cupola 16980:duals: 16966:prisms 16644:cupola 16520:vertex 16222:  16183:  16175:  16097:  16078:  16070:  16039:  15969:  15832:  15798:  15684:26 May 15622:  15436:  15401:  15281:  15144:  14649:, and 14542:Radius 14304:Since 14207:. The 14052:by, a 13488:V4.6.6 13478:V3.3.3 13473:V3.6.6 13463:V3.6.6 13458:V3.3.3 13368:t{3,3} 13363:r{3,3} 13358:t{3,3} 12984:image 12943:image 12895:image 12593:digons 12453:Square 12136:  12124:  11967:  11118:, and 11098:, and 10951:, and 10926:, and 10674:. The 10143:, but 10061:where 9604:median 9377:, the 8888:where 8687:, and 8587:, and 8147:where 7961:, and 7901:, and 7171:where 6967:, and 6879:where 6727:  6723:  6533:Hence 6527:  6326:  6322:  6252:  6248:  5756:where 5710:Volume 4987:Schön. 3144:Kepler 3015:5-cell 2996:chiral 2901:wedges 2897:square 2881:square 2835:Image 1805:arccos 1768:arcsin 1721:arccos 1679:median 915:, and 777:arctan 738:arccos 722:70.529 692:arctan 661:arccos 224:convex 17256:p-gon 16649:wedge 16629:prism 16489:(132) 16197:(PDF) 16115:(PDF) 16076:S2CID 16068:JSTOR 15756:(PDF) 15745:(PDF) 15719:(PDF) 15704:(PDF) 15573:(PDF) 15399:JSTOR 15344:(PDF) 15312:(PDF) 15279:JSTOR 15261:arXiv 15247:(PDF) 14762:Notes 14639:graph 14562:Girth 14532:Edges 14342:Games 14231:Water 14189:ion ( 13903:{∞,3} 13898:{8,3} 13893:{7,3} 13888:{6,3} 13883:{5,3} 13878:{4,3} 13873:{3,3} 13868:{2,3} 13373:{3,3} 13353:{3,3} 12850:name 12364:Faces 11961:where 6725:where 6324:where 6155:graph 5019:Four 4932:above 4916:nodes 4891:of a 4140:0.408 4050:0.707 3960:1.225 3784:0.577 3559:1.155 3402:edge 3220:of a 3128:In a 2879:is a 2830:Edge 1858:spats 1700:proof 1653:slope 947:are: 617:0.118 451:1.732 243:Plato 86:edges 82:faces 40:, or 17614:cube 17287:Cube 17117:and 16730:cube 16611:(57) 16582:(92) 16576:(13) 16570:(13) 16539:(16) 16515:edge 16510:face 16483:(90) 16477:(60) 16471:(48) 16465:(32) 16459:(30) 16453:(24) 16220:ISBN 16173:ISSN 16095:ISBN 16037:ISBN 15967:ISBN 15880:2012 15830:ISBN 15796:OCLC 15764:2009 15727:2006 15686:2024 15620:ISBN 15503:2018 15434:PMID 15326:link 15142:ISSN 14707:and 14633:The 14401:The 14383:and 14356:The 14297:are 14287:and 14132:The 14015:The 14008:The 13989:and 13732:,3} 13016:... 12933:... 12882:... 12818:... 12731:... 12676:... 12578:... 12531:... 12470:... 11429:and 11252:for 10906:Let 10445:Let 10163:cf. 10123:and 10079:The 10072:and 9633:The 9464:here 9432:and 9011:and 8001:is: 7861:Let 7838:and 7223:and 7211:and 7199:and 5778:base 5098:*332 5074:and 5002:Ord. 4997:Orb. 4992:Cox. 4967:Edge 3405:arc 3222:tree 3021:and 2730:1 ± 2558:cube 2500:and 2459:dual 2271:cube 1705:Its 1675:apex 645:Its 254:dual 247:fire 186:The 138:nets 56:, a 17163:(p) 16764:or 16599:(4) 16564:(5) 16533:(9) 16495:(∞) 16163:doi 16060:doi 15910:doi 15657:doi 15553:doi 15426:doi 15391:doi 15271:doi 15257:110 15132:doi 15128:472 15040:doi 14888:333 14653:, W 14645:, K 14473:in 14068:of 14044:In 13660:3.3 13504:{3, 12411:600 12408:185 12406:124 12401:120 12394:800 12392:436 12130:and 11402:If 10868:cos 10826:cos 10784:cos 10380:sin 10359:sin 10338:sin 10317:sin 10296:sin 10275:sin 10167:). 10002:cos 9976:cos 9950:cos 9922:cos 9888:cos 9862:cos 9834:cos 9808:cos 9774:cos 9746:cos 9720:cos 9694:cos 8861:192 8449:cos 8428:cos 8407:cos 8392:cos 8381:cos 8370:cos 7485:288 7262:det 7136:cos 7115:cos 7094:cos 7079:cos 7068:cos 7057:cos 6846:cos 6806:cos 6766:cos 6090:det 5669:to 5597:or 5564:*22 5485:222 5427:or 5385:2*2 5171:*33 5121:An 5105:12 5100:332 3845:60° 3756:𝟁 3718:60° 3646:𝝉 3608:60° 3531:𝟀 3413:𝒍 3208:An 3134:one 3098:An 3079:An 3005:In 2715:): 1923:and 1702:). 264:or 68:or 62:pl. 52:In 17683:: 17668:• 17664:• 17644:21 17640:• 17637:k1 17633:• 17630:k2 17608:• 17565:• 17535:• 17513:21 17509:• 17506:41 17502:• 17499:42 17485:• 17463:21 17459:• 17456:31 17452:• 17449:32 17435:• 17413:21 17409:• 17406:22 17392:• 17362:• 17341:• 17322:• 17301:• 17285:• 17217:/ 17206:/ 17196:/ 17187:/ 17165:/ 16622:‌s 16248:. 16207:16 16205:. 16199:. 16181:MR 16179:. 16171:. 16159:13 16157:. 16153:. 16140:. 16074:. 16066:. 16056:36 16054:. 16035:. 16031:. 15986:24 15984:. 15965:. 15961:. 15934:. 15906:55 15904:. 15900:. 15856:. 15828:. 15826:32 15794:. 15747:. 15712:75 15710:. 15706:. 15677:. 15655:. 15645:22 15643:. 15596:, 15581:11 15579:, 15549:29 15547:, 15493:. 15476:, 15458:^ 15432:. 15422:10 15420:. 15397:. 15387:54 15385:. 15361:. 15322:}} 15318:{{ 15277:. 15269:. 15255:. 15249:. 15198:^ 15179:68 15163:67 15140:. 15126:. 15122:. 15080:". 15054:^ 15036:17 15034:. 15030:. 14950:68 14911:^ 14904:55 14837:. 14822:^ 14787:^ 14711:– 14665:. 14617:, 14613:, 14609:, 14605:, 14601:, 14597:, 14576:24 14387:. 14275:. 14233:, 14191:NH 14175:CH 14108:. 14092:, 14088:, 14084:, 14080:, 14076:, 13718:. 13708:3 13705:3 13702:3 13699:3 13526:} 13512:. 13049:: 12859:) 12595:. 12429:. 12414:. 12399:47 12360:. 11845:24 11692:, 11688:, 11680:, 11676:, 11660:. 11420:, 11411:, 11114:, 11110:, 11094:, 11090:, 10944:, 10937:, 10922:, 10918:, 10526:, 10499:, 10472:, 10260:, 10256:, 10252:, 10197:. 10111:, 10093:sr 10076:. 10065:ij 10017:34 9991:24 9965:14 9937:34 9903:23 9877:13 9849:24 9823:23 9789:12 9761:14 9735:13 9709:12 9591:. 8647:, 8567:. 8547:, 8527:, 8507:, 8133:12 7941:, 7881:, 7842:ij 7832:, 7828:, 7824:, 7812:, 7772:34 7755:24 7738:14 7714:34 7692:23 7675:13 7651:24 7634:23 7612:12 7588:14 7571:13 7554:12 7474:: 7227:. 7179:, 7175:, 6923:, 6544:36 6250:or 5660:A 5641:2 5638:22 5622:. 5615:, 5571:2 5566:22 5550:2v 5529:2v 5488:4 5392:4 5387:2× 5373:2d 5333:2d 5294:1 5252:2 5243:1v 5235:1h 5218:. 5211:, 5178:3 5173:33 5159:3v 5143:, 5137:3v 5103:24 5036:, 4938:. 4903:. 4836:A 4828:. 4795:, 4762:, 4696:, 4663:, 4597:, 4564:, 4505:, 4472:, 4413:, 4380:, 4310:, 4288:, 3326:. 3193:A 3172:A 3095:. 3076:. 3017:, 3002:. 2903:. 2813:. 2768:, 2764:, 2738:± 2734:± 2568:. 2540:. 2266:. 1860:. 1736:27 1733:23 1279:16 1014:24 883:, 860:, 295:. 214:A 151:) 140:. 114:. 96:. 64:: 34:, 17652:- 17650:n 17642:k 17635:2 17628:1 17621:- 17619:n 17612:- 17610:n 17604:- 17602:n 17595:- 17593:n 17586:- 17584:n 17511:4 17504:2 17497:1 17461:3 17454:2 17447:1 17411:2 17404:1 17233:n 17231:H 17224:2 17221:G 17213:4 17210:F 17202:8 17199:E 17193:7 17190:E 17184:6 17181:E 17172:n 17168:D 17161:2 17158:I 17150:n 17146:B 17138:n 17134:A 17106:e 17099:t 17092:v 17076:. 16768:) 16760:( 16717:) 16713:( 16693:e 16686:t 16679:v 16300:e 16293:t 16286:v 16273:. 16254:. 16228:. 16187:. 16165:: 16142:4 16103:. 16082:. 16062:: 16045:. 16020:. 15975:. 15940:. 15916:. 15912:: 15882:. 15838:. 15802:. 15790:: 15766:. 15729:. 15688:. 15663:. 15659:: 15651:: 15629:. 15555:: 15540:p 15537:L 15505:. 15479:. 15474:” 15453:. 15440:. 15428:: 15405:. 15393:: 15363:8 15328:) 15285:. 15273:: 15263:: 15232:. 15220:. 15181:. 15165:. 15148:. 15134:: 15108:. 15078:3 15048:. 15042:: 15000:. 14987:. 14952:. 14906:. 14890:. 14874:. 14843:. 14794:( 14713:n 14655:4 14647:4 14586:4 14566:3 14556:1 14546:1 14536:6 14526:4 14269:t 14244:O 14240:2 14235:H 14222:3 14219:/ 14216:1 14196:4 14180:4 13752:e 13745:t 13738:v 13730:n 13726:n 13724:* 13695:3 13690:3 13685:3 13680:3 13675:3 13670:3 13665:3 13546:e 13539:t 13532:v 13524:n 13520:n 13518:* 13506:n 12855:( 12840:n 12629:e 12622:t 12615:v 12604:n 12324:) 12315:2 12305:0 12301:x 12289:2 12279:3 12275:x 12262:2 12252:0 12248:x 12236:2 12226:2 12222:x 12209:2 12199:0 12195:x 12183:2 12173:1 12169:x 12158:( 12152:2 12149:1 12144:= 12141:B 12118:) 12109:T 12104:] 12098:0 12094:x 12085:3 12081:x 12076:[ 12065:T 12060:] 12054:0 12050:x 12041:2 12037:x 12032:[ 12021:T 12016:] 12010:0 12006:x 11997:1 11993:x 11988:[ 11979:( 11975:= 11972:A 11955:B 11950:1 11943:A 11939:= 11932:C 11914:3 11911:x 11908:, 11905:2 11902:x 11899:, 11896:1 11893:x 11890:, 11887:0 11884:x 11878:C 11854:. 11848:V 11840:) 11837:C 11834:c 11831:+ 11828:B 11825:b 11822:+ 11819:A 11816:a 11810:( 11807:) 11804:C 11801:c 11798:+ 11795:B 11792:b 11786:A 11783:a 11780:( 11777:) 11774:C 11771:c 11765:B 11762:b 11759:+ 11756:A 11753:a 11750:( 11747:) 11744:C 11741:c 11738:+ 11735:B 11732:b 11729:+ 11726:A 11723:a 11720:( 11714:= 11711:R 11698:V 11694:C 11690:B 11686:A 11682:c 11678:b 11674:a 11670:R 11648:r 11643:4 11639:A 11633:3 11630:1 11625:+ 11622:r 11617:3 11613:A 11607:3 11604:1 11599:+ 11596:r 11591:2 11587:A 11581:3 11578:1 11573:+ 11570:r 11565:1 11561:A 11555:3 11552:1 11547:= 11544:V 11531:. 11514:4 11510:A 11506:+ 11501:3 11497:A 11493:+ 11488:2 11484:A 11480:+ 11475:1 11471:A 11465:V 11462:3 11456:= 11453:r 11440:r 11435:4 11431:A 11426:3 11422:A 11417:2 11413:A 11408:1 11404:A 11384:, 11377:2 11373:r 11369:2 11357:2 11352:4 11348:r 11344:1 11339:+ 11332:2 11327:3 11323:r 11319:1 11314:+ 11307:2 11302:2 11298:r 11294:1 11289:+ 11282:2 11277:1 11273:r 11269:1 11254:i 11249:i 11245:r 11237:r 11215:. 11212:) 11209:M 11206:P 11203:+ 11200:L 11197:P 11194:+ 11191:K 11188:P 11185:+ 11182:J 11179:P 11176:( 11173:3 11167:D 11164:P 11161:+ 11158:C 11155:P 11152:+ 11149:B 11146:P 11143:+ 11140:A 11137:P 11124:P 11120:M 11116:L 11112:K 11108:J 11104:P 11100:D 11096:C 11092:B 11088:A 11071:. 11068:V 11065:9 11056:d 11051:F 11044:D 11041:P 11038:+ 11032:c 11027:F 11020:C 11017:P 11014:+ 11008:b 11003:F 10996:B 10993:P 10990:+ 10984:a 10979:F 10972:A 10969:P 10956:d 10953:F 10949:c 10946:F 10942:b 10939:F 10935:a 10932:F 10928:D 10924:C 10920:B 10916:A 10912:V 10908:P 10887:) 10882:j 10879:i 10863:l 10853:k 10845:+ 10840:k 10837:i 10821:l 10811:j 10803:+ 10798:l 10795:i 10779:k 10769:j 10761:( 10758:2 10750:2 10745:l 10737:+ 10732:2 10727:k 10719:+ 10714:2 10709:j 10701:= 10696:2 10691:i 10660:j 10656:P 10650:i 10646:P 10623:j 10620:i 10593:i 10589:P 10566:i 10539:4 10535:P 10512:3 10508:P 10485:2 10481:P 10458:1 10454:P 10419:O 10398:. 10395:A 10392:B 10389:O 10374:B 10371:C 10368:O 10353:C 10350:A 10347:O 10335:= 10332:A 10329:C 10326:O 10311:C 10308:B 10305:O 10290:B 10287:A 10284:O 10262:C 10258:B 10254:A 10250:O 10145:O 10141:v 10137:M 10133:v 10129:v 10125:M 10121:O 10117:v 10113:M 10105:O 10101:O 10097:O 10089:O 10074:j 10070:i 10063:α 10045:0 10042:= 10037:| 10031:1 10022:) 10009:( 9996:) 9983:( 9970:) 9957:( 9942:) 9929:( 9917:1 9908:) 9895:( 9882:) 9869:( 9854:) 9841:( 9828:) 9815:( 9803:1 9794:) 9781:( 9766:) 9753:( 9740:) 9727:( 9714:) 9701:( 9689:1 9680:| 9658:T 9654:M 9650:T 9553:. 9548:6 9543:| 9539:) 9535:) 9532:c 9526:b 9523:( 9515:a 9511:( 9507:| 9503:d 9497:= 9494:V 9474:V 9449:c 9441:b 9420:a 9400:d 9344:. 9341:) 9338:W 9335:+ 9332:v 9326:u 9323:( 9319:) 9316:v 9313:+ 9310:u 9304:W 9301:( 9298:= 9295:z 9289:, 9286:) 9283:v 9280:+ 9277:u 9274:+ 9271:W 9268:( 9265:) 9262:u 9259:+ 9256:W 9250:v 9247:( 9244:= 9241:Z 9234:, 9231:) 9228:V 9225:+ 9222:u 9216:w 9213:( 9210:) 9207:u 9204:+ 9201:w 9195:V 9192:( 9189:= 9186:y 9180:, 9177:) 9174:u 9171:+ 9168:w 9165:+ 9162:V 9159:( 9156:) 9153:w 9150:+ 9147:V 9141:u 9138:( 9135:= 9132:Y 9125:, 9122:) 9119:U 9116:+ 9113:w 9107:v 9104:( 9101:) 9098:w 9095:+ 9092:v 9086:U 9083:( 9080:= 9077:x 9071:, 9068:) 9065:w 9062:+ 9059:v 9056:+ 9053:U 9050:( 9047:) 9044:v 9041:+ 9038:U 9032:w 9029:( 9026:= 9023:X 8995:, 8990:z 8987:y 8984:x 8979:= 8976:s 8970:, 8965:Y 8962:X 8959:z 8954:= 8951:r 8944:, 8939:X 8936:Z 8933:y 8928:= 8925:q 8919:, 8914:Z 8911:Y 8908:x 8903:= 8900:p 8873:w 8869:v 8865:u 8856:) 8853:s 8847:r 8844:+ 8841:q 8838:+ 8835:p 8832:( 8828:) 8825:s 8822:+ 8819:r 8813:q 8810:+ 8807:p 8804:( 8800:) 8797:s 8794:+ 8791:r 8788:+ 8785:q 8779:p 8776:( 8772:) 8769:s 8766:+ 8763:r 8760:+ 8757:q 8754:+ 8751:p 8745:( 8738:= 8735:V 8715:W 8695:w 8675:V 8655:v 8635:U 8615:u 8595:w 8575:v 8555:u 8535:W 8515:V 8495:U 8453:2 8432:2 8411:2 8367:2 8364:+ 8361:1 8354:6 8350:c 8347:b 8344:a 8338:= 8335:V 8311:. 8306:2 8302:z 8293:2 8289:b 8285:+ 8280:2 8276:a 8272:= 8265:Z 8258:, 8253:2 8249:y 8240:2 8236:c 8232:+ 8227:2 8223:a 8219:= 8212:Y 8205:, 8200:2 8196:x 8187:2 8183:c 8179:+ 8174:2 8170:b 8166:= 8159:X 8129:Z 8126:Y 8123:X 8120:+ 8115:2 8111:Z 8105:2 8101:c 8092:2 8088:Y 8082:2 8078:b 8069:2 8065:X 8059:2 8055:a 8046:2 8042:c 8036:2 8032:b 8026:2 8022:a 8018:4 8012:= 8009:V 7989:V 7969:z 7949:y 7929:x 7909:c 7889:b 7869:a 7840:d 7836:} 7834:d 7830:c 7826:b 7822:a 7820:{ 7814:j 7810:i 7790:| 7784:0 7777:2 7768:d 7760:2 7751:d 7743:2 7734:d 7728:1 7719:2 7710:d 7704:0 7697:2 7688:d 7680:2 7671:d 7665:1 7656:2 7647:d 7639:2 7630:d 7624:0 7617:2 7608:d 7602:1 7593:2 7584:d 7576:2 7567:d 7559:2 7550:d 7544:0 7539:1 7532:1 7527:1 7522:1 7517:1 7512:0 7506:| 7501:= 7496:2 7492:V 7455:. 7450:| 7445:) 7438:1 7433:1 7428:1 7423:1 7414:3 7410:d 7402:3 7398:c 7390:3 7386:b 7378:3 7374:a 7364:2 7360:d 7352:2 7348:c 7340:2 7336:b 7328:2 7324:a 7314:1 7310:d 7302:1 7298:c 7290:1 7286:b 7278:1 7274:a 7266:( 7258:| 7254:= 7251:V 7245:6 7232:d 7225:b 7221:a 7217:γ 7213:c 7209:a 7205:β 7201:c 7197:b 7193:d 7189:α 7185:d 7181:γ 7177:β 7173:α 7155:, 7140:2 7119:2 7098:2 7054:2 7051:+ 7048:1 7041:6 7037:c 7034:b 7031:a 7025:= 7022:V 6990:c 6978:= 6975:c 6946:b 6934:= 6931:b 6902:a 6890:= 6887:a 6857:. 6843:c 6840:a 6837:= 6833:c 6825:a 6817:, 6803:c 6800:b 6797:= 6793:c 6785:b 6777:, 6763:b 6760:a 6757:= 6753:b 6745:a 6738:{ 6708:| 6699:2 6695:c 6687:c 6679:b 6672:c 6664:a 6655:c 6647:b 6638:2 6634:b 6626:b 6618:a 6609:c 6601:a 6594:b 6586:a 6577:2 6573:a 6565:| 6560:= 6555:2 6551:V 6507:, 6504:) 6499:3 6495:c 6491:, 6486:2 6482:c 6478:, 6473:1 6469:c 6465:( 6462:= 6458:c 6450:, 6447:) 6442:3 6438:b 6434:, 6429:2 6425:b 6421:, 6416:1 6412:b 6408:( 6405:= 6401:b 6393:, 6390:) 6385:3 6381:a 6377:, 6372:2 6368:a 6364:, 6359:1 6355:a 6351:( 6348:= 6344:a 6337:{ 6300:c 6291:b 6282:a 6270:= 6267:V 6261:6 6226:c 6219:b 6212:a 6200:= 6197:V 6191:6 6172:6 6169:/ 6166:1 6141:) 6137:d 6129:c 6125:, 6121:d 6113:b 6109:, 6105:d 6097:a 6093:( 6085:6 6082:1 6053:. 6050:) 6045:3 6041:d 6037:, 6032:2 6028:d 6024:, 6019:1 6015:d 6011:( 6008:= 6000:d 5992:, 5989:) 5984:3 5980:c 5976:, 5971:2 5967:c 5963:, 5958:1 5954:c 5950:( 5947:= 5939:c 5931:, 5928:) 5923:3 5919:b 5915:, 5910:2 5906:b 5902:, 5897:1 5893:b 5889:( 5886:= 5878:b 5870:, 5867:) 5862:3 5858:a 5854:, 5849:2 5845:a 5841:, 5836:1 5832:a 5828:( 5825:= 5817:a 5788:h 5764:A 5744:. 5741:h 5738:A 5733:3 5730:1 5725:= 5722:V 5687:2 5683:/ 5679:3 5632:2 5629:C 5620:2 5617:Z 5609:2 5606:C 5569:4 5557:2 5554:C 5547:C 5539:4 5536:V 5526:C 5479:2 5476:D 5439:2 5436:D 5432:2 5429:Z 5425:4 5422:V 5390:8 5378:4 5376:S 5370:D 5330:D 5291:1 5285:1 5283:C 5249:* 5240:C 5238:= 5232:C 5230:= 5227:s 5224:C 5216:2 5213:Z 5205:s 5202:C 5176:6 5164:3 5162:C 5156:C 5148:3 5145:S 5134:C 5091:T 5087:d 5084:T 5041:4 5038:S 5030:d 5027:T 4956:4 4952:3 4811:6 4808:1 4778:2 4775:3 4745:3 4742:4 4712:6 4709:1 4679:2 4676:1 4646:3 4643:1 4613:2 4610:1 4580:2 4577:3 4551:1 4521:6 4518:1 4488:3 4485:1 4459:1 4429:6 4426:1 4396:2 4393:1 4363:2 4360:3 4326:3 4323:1 4297:1 4271:3 4268:4 4230:2 4226:3 4130:6 4127:1 4100:l 4096:/ 4092:R 4087:2 4040:2 4037:1 4010:l 4006:/ 4002:R 3997:1 3950:2 3947:3 3920:l 3916:/ 3912:R 3907:0 3863:3 3818:2 3774:3 3771:1 3736:3 3691:2 3657:1 3626:3 3587:2 3549:3 3546:4 3497:2 3458:2 3424:2 3315:3 3252:3 3245:2 2883:. 2808:2 2787:x 2783:x 2773:) 2770:k 2766:j 2762:i 2752:) 2747:2 2744:/ 2740:k 2736:j 2732:i 2693:4 2689:A 2664:T 2637:4 2633:S 2602:d 2596:T 2528:} 2525:3 2522:, 2519:4 2516:{ 2512:h 2443:2 2438:2 2414:. 2411:) 2408:1 2405:, 2402:1 2396:, 2393:1 2387:( 2379:, 2376:) 2373:1 2367:, 2364:1 2361:, 2358:1 2352:( 2345:, 2342:) 2339:1 2333:, 2330:1 2324:, 2321:1 2318:( 2310:, 2307:) 2304:1 2301:, 2298:1 2295:, 2292:1 2289:( 2252:3 2246:6 2241:2 2214:) 2211:1 2208:, 2205:0 2202:, 2199:0 2196:( 2188:, 2184:) 2178:3 2175:1 2167:, 2161:3 2158:2 2149:, 2143:9 2140:2 2130:( 2122:, 2118:) 2112:3 2109:1 2101:, 2095:3 2092:2 2086:, 2080:9 2077:2 2067:( 2060:, 2056:) 2050:3 2047:1 2039:, 2036:0 2033:, 2027:9 2024:8 2017:( 1992:y 1989:x 1962:) 1955:2 1951:1 1946:, 1943:1 1937:, 1934:0 1930:( 1916:) 1909:2 1905:1 1897:, 1894:0 1891:, 1888:1 1881:( 1825:) 1820:3 1817:1 1812:( 1802:3 1799:= 1788:) 1783:3 1780:1 1775:( 1765:3 1757:2 1749:= 1741:) 1728:( 1695:C 1691:C 1683:C 1666:2 1659:2 1633:. 1628:2 1623:) 1617:2 1612:4 1608:d 1604:+ 1599:2 1594:3 1590:d 1586:+ 1581:2 1576:2 1572:d 1568:+ 1563:2 1558:1 1554:d 1550:+ 1545:2 1541:a 1536:( 1531:= 1523:) 1517:4 1512:4 1508:d 1504:+ 1499:4 1494:3 1490:d 1486:+ 1481:4 1476:2 1472:d 1468:+ 1463:4 1458:1 1454:d 1450:+ 1445:4 1441:a 1436:( 1432:4 1425:, 1420:2 1415:) 1409:3 1403:2 1399:R 1395:2 1389:+ 1384:4 1378:2 1373:4 1369:d 1365:+ 1360:2 1355:3 1351:d 1347:+ 1342:2 1337:2 1333:d 1329:+ 1324:2 1319:1 1315:d 1307:( 1302:= 1293:9 1287:4 1283:R 1273:+ 1268:4 1262:4 1257:4 1253:d 1249:+ 1244:4 1239:3 1235:d 1231:+ 1226:4 1221:2 1217:d 1213:+ 1208:4 1203:1 1199:d 1169:i 1165:d 1144:R 1124:a 1100:. 1094:6 1090:a 1085:= 1079:E 1074:r 1067:, 1061:8 1057:a 1052:= 1047:R 1044:r 1039:= 1033:M 1028:r 1020:, 1010:a 1005:= 1002:R 997:3 994:1 989:= 986:r 980:, 977:a 972:4 968:6 962:= 959:R 932:E 927:r 900:M 895:r 871:r 848:R 811:. 794:) 789:2 784:( 774:2 771:= 763:) 757:3 754:1 745:( 731:, 714:) 708:2 703:2 699:( 689:= 681:) 676:3 673:1 668:( 630:. 625:3 621:a 606:2 601:6 595:3 591:a 585:= 582:a 577:3 573:6 563:) 557:2 553:a 547:4 543:3 536:( 527:3 524:1 519:= 516:V 496:a 491:3 487:6 464:. 459:2 455:a 443:3 436:2 432:a 428:= 424:) 418:2 414:a 408:4 404:3 397:( 390:4 387:= 384:A 364:A 344:a 60:( 47:. 20:)

Index

Tetrahedral angle
tetrahedroid
Tetraedron
Tetrahedron (journal)
geometry
polyhedron
faces
edges
vertices
convex polyhedra
three-dimensional
Euclidean
simplex
pyramid
polygon
triangle
convex polyhedra
nets
circumsphere
insphere
tangent


stella octangula

a thin volume of empty space
equilateral triangles
convex
deltahedron
Platonic solids

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