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Equilateral triangle

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3554: 3326: 2553: 239: 47: 6558: 6601: 3341:. Draw a straight line, and place the point of the compass on one end of the line, and swing an arc from that point to the other point of the line segment. Repeat with the other side of the line. Finally, connect the point where the two arcs intersect with each end of the line segment. 4225:
is a circle (specifically, the incircle). The triangle of largest area of all those inscribed in a given circle is equilateral, and the triangle of smallest area of all those circumscribed around a given circle is also equilateral. It is the only regular polygon aside from the
3364:, place the point of the compass on the circle and draw another circle with the same radius. The two circles will intersect in two points. An equilateral triangle can be constructed by taking the two centers of the circles and either of the points of intersection. 4154: 4831: 1338: 1200:
any one of the statements in the following nine categories is true. Thus these are properties that are unique to equilateral triangles, and knowing that any one of them is true directly implies that we have an equilateral triangle.
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states that, if equilateral triangles are constructed on the sides of any triangle, either all outward, or all inward, the centers of those equilateral triangles themselves form an equilateral triangle.
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in the interior of an equilateral triangle, the ratio of the sum of its distances from the vertices to the sum of its distances from the sides is greater than or equal to 2, equality holding when
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connecting some of the centers. For some pairs of triangle centers, the fact that they coincide is enough to ensure that the triangle is equilateral. In particular:
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equilateral triangles. Specifically for star antiprisms, there are prograde and retrograde (crossed) solutions that join mirrored and non-mirrored parallel
2439: 1005: 6566: 6675:, which is the first true member of the infinite family of antiprisms (the tetrahedron, as a digonal antiprism, is sometimes considered the first). 7554: 6100: 3313:
is on the circumcircle then the sum of the two smaller ones equals the longest and the triangle has degenerated into a line, this case is known as
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A triangle is equilateral if and only if the circumcenters of any three of the smaller triangles have the same distance from the centroid.
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In an equilateral triangle, the altitudes, the angle bisectors, the perpendicular bisectors, and the medians to each side coincide.
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Riley, Michael W.; Cochran, David J.; Ballard, John L. (December 1982). "An Investigation of Preferred Shapes for Warning Labels".
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A triangle is equilateral if and only if any three of the smaller triangles have either the same perimeter or the same inradius.
5012: 3915: 2259: 1650: 7113: 7002: 6776: 5661: 2244: 1193: 516: 6632:. All Platonic solids can inscribe tetrahedra, as well as be inscribed inside tetrahedra. Equilateral triangles also form 6628:. In particular, the tetrahedron, which has four equilateral triangles for faces, can be considered the three-dimensional 8002: 7158: 6986: 6980: 3512: 8597: 7907: 7880: 7847: 7699: 7650: 4284: 1351: 2061: 655: 7174: 6812: 6001: 4149:{\displaystyle A={\frac {1}{2}}ab\times {\frac {\sqrt {3}}{2}}={\frac {\sqrt {3}}{4}}ab={\frac {\sqrt {3}}{4}}a^{2}} 394: 3399: 17: 6167: 1551: 714: 136: 9132: 6208: 4357: 707:
Many of these quantities have simple relationships to the altitude ("h") of each vertex from the opposite side:
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is the centroid. In no other triangle is there a point for which this ratio is as small as 2. This is the
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The legs of either right triangle formed by an altitude of the equilateral triangle are half of the base
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The proof that the resulting figure is an equilateral triangle is the first proposition in Book I of
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If a segment splits an equilateral triangle into two regions with equal perimeters and with areas
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two dimensional space with six triangles meeting at a vertex, whose dual tessellation is the
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The geometric center of the triangle is the center of the circumscribed and inscribed circles
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of the equilateral triangle. The height of an equilateral triangle can be found using the
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As these triangles are equilateral, their altitudes can be rotated to be vertical.
9076: 9056: 9051: 9021: 8740: 8715: 8647: 8153: 8138: 7705: 7587: 7008: 6835: 4214: 2224: 223: 64: 57: 7453:"Curious properties of the circumcircle and incircle of an equilateral triangle" 6678:
As a generalization, the equilateral triangle belongs to the infinite family of
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states that, in any triangle, the three points of intersection of the adjacent
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Blundon, W. J. (1963). "On Certain Polynomials Associated with the Triangle".
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In three dimensions, equilateral triangles form faces of regular and uniform
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can be derived directly using the Pythagorean theorem or using trigonometry.
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Minda, D.; Phelps, S. (2008). "Triangles, ellipses, and cubic polynomials".
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An equilateral triangle is the most symmetrical triangle, having 3 lines of
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Equilateral triangles have frequently appeared in man made constructions:
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The shape occurs in modern architecture such as the cross-section of the
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Denoting the common length of the sides of the equilateral triangle as
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Human Factors: The Journal of the Human Factors and Ergonomics Society
4241:, the equilateral triangle has the smallest ratio of the circumradius 2537:{\displaystyle 4\left(p^{2}+q^{2}+r^{2}\right)\geq x^{2}+y^{2}+z^{2}.} 2266: 8980: 8970: 8947: 8937: 8927: 8856: 8765: 8730: 8511: 8425: 8375: 8325: 8282: 8252: 8221: 7971: 6985:. Dolciani Mathematical Expositions. Vol. 36. Washington, D.C.: 6609: 4231: 2925: 7575: 6938: 4539:
that hold with equality if and only if the triangle is equilateral.
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on the inscribed circle of an equilateral triangle, with distances
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coincide, and are equal, for (and only for) equilateral triangles:
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Construction of equilateral triangle with compass and straightedge
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can be slid up to show that the altitudes sum to that of triangle
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copies of regular polygons are connected by alternating bands of
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Conway, J. H., and Guy, R. K., "The only rational triangle", in
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Florida Atlantic University, Department of Mathematical Sciences
7157:. Classroom Resource Materials. Vol. 37. Washington, D.C.: 2560:
Nearest distances from point P to sides of equilateral triangle
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in three-dimensional space. For antiprisms, two (non-mirrored)
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in which all three sides have the same length. In the familiar
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that the sum of any two of them is greater than the third. If
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is an arbitrary point in the plane of an equilateral triangle
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It is also equilateral if its circumcenter coincides with the
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The radius of the circle circumscribing the three vertices is
8795: 7961: 6146:{\displaystyle {\frac {1}{q}}+{\frac {1}{t}}={\frac {1}{y}},} 215: 7329:
Leon Bankoff and Jack Garfunkel, "The heptagonal triangle",
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A regular tetrahedron is made of four equilateral triangles.
5003:{\displaystyle p^{2}+q^{2}+t^{2}=3\left(R^{2}+L^{2}\right),} 1942:{\displaystyle T={\frac {\sqrt {3}}{4}}(abc)^{\frac {2}{3}}} 8184: 7055:"A new proof of Euler's inradius - circumradius inequality" 6869:
Dospinescu, G.; Lascu, M.; Pohoata, C.; Letiva, M. (2008).
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Chakerian, G. D. "A Distorted View of Geometry." Ch. 7 in
5452:{\displaystyle 16\left(p^{4}+q^{4}+t^{4}\right)=11a^{4}.} 3557:
An equilateral triangle with a side of 2 has a height of
1709:{\displaystyle \cos {A}+\cos {B}+\cos {C}={\frac {3}{2}}} 6878:
Journal of Inequalities in Pure and Applied Mathematics
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Journal of Inequalities in Pure and Applied Mathematics
5368:{\displaystyle 4\left(p^{2}+q^{2}+t^{2}\right)=5a^{2},} 6548:{\displaystyle z_{1}+\omega z_{2}+\omega ^{2}z_{3}=0.} 6205:
The ratio of its area to the square of its perimeter,
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since all sides of an equilateral triangle are equal.
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An alternative method is to draw a circle with radius
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An equilateral triangle is easily constructed using a
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Pelkonen, Eeva-Liisa; Albrecht, Donald, eds. (2006).
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gives the area formula for the equilateral triangle:
3766: 3746: 3703: 3635: 3612: 3592: 3515: 3495: 3475: 3447: 3402: 3350: 3299: 3272: 3249: 3226: 3203: 3180: 3157: 3151:, then there exists a triangle with sides of lengths 3127: 3107: 3081: 3040: 3020: 3000: 2980: 2960: 2940: 2872: 2846: 2817: 2785: 2759: 2733: 2710: 2687: 2664: 2641: 2618: 2595: 2566: 2442: 2422: 2402: 2382: 2362: 2342: 2322: 2302: 2133: 2064: 1994: 1963: 1893: 1809: 1723: 1653: 1607: 1554: 1517: 1473: 1417: 1354: 1248: 1215: 1174: 1154: 1134: 1114: 1094: 1067: 1040: 1013: 990: 967: 944: 924: 904: 878: 834: 794: 765: 717: 658: 605: 563: 525: 484: 447: 397: 369: 312: 280: 248: 139: 7298:
Posamentier, Alfred S.; Salkind, Charles T. (1996).
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Its applications in flags and heraldry includes the
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is larger than that of any non-equilateral triangle.
7922: 6164:The ratio of its area to the area of the incircle, 4016:{\displaystyle A={\frac {1}{2}}ab\sin 60^{\circ }.} 2920:for triangles states that the triangle of greatest 2275:partition the triangle into six smaller triangles. 2267:
Six triangles formed by partitioning by the medians
640:Denoting the radius of the circumscribed circle as 7864: 7794: 7683: 7411:Gardner, Martin, "Elegant Triangles", in the book 7299: 7297: 7150: 7089: 6720: 6690: 6659: 6547: 6475: 6455: 6428: 6401: 6368: 6295: 6268: 6236: 6192: 6145: 6089: 6063: 5990: 5915: 5895: 5872: 5852: 5829: 5806: 5783: 5760: 5737: 5715: 5651: 5616: 5596: 5576: 5556: 5536: 5516: 5496: 5473: 5451: 5367: 5282: 5262: 5242: 5222: 5199: 5179: 5159: 5139: 5002: 4907: 4887: 4867: 4847: 4825: 4674: 4654: 4634: 4614: 4594: 4574: 4554: 4527: 4507: 4487: 4467: 4438: 4409: 4376: 4348: 4328: 4306: 4273: 4253: 4201: 4148: 4048: 4015: 3955: 3904: 3884: 3864: 3833: 3785: 3752: 3730: 3689: 3618: 3598: 3543: 3501: 3481: 3453: 3433: 3356: 3305: 3281: 3258: 3235: 3212: 3189: 3166: 3139: 3113: 3087: 3067: 3026: 3006: 2986: 2966: 2946: 2884: 2858: 2832: 2797: 2771: 2745: 2719: 2696: 2673: 2650: 2627: 2604: 2578: 2536: 2428: 2408: 2388: 2368: 2348: 2328: 2308: 2172: 2118: 2049: 1978: 1941: 1873: 1787: 1708: 1638: 1585: 1539: 1502: 1458: 1401: 1332: 1233: 1180: 1160: 1140: 1120: 1100: 1080: 1053: 1026: 996: 973: 950: 930: 910: 890: 853: 818: 778: 745: 696: 629: 582: 549: 505: 464: 431: 375: 351: 298: 266: 166: 30:"Equilateral" redirects here. For other uses, see 6982:When less is more. Visualizing basic inequalities 6811:Bencze, Mihály; Wu, Hui-Hua; Wu, Shan-He (2008). 3965:Each angle of an equilateral triangle is 60°, so 3367:In both methods a by-product is the formation of 1402:{\displaystyle s=2R+\left(3{\sqrt {3}}-4\right)r} 461: 9119: 7831: 7789: 7427:"Cyclic Averages of Regular Polygonal Distances" 7261:"Inequalities proposed in "Crux Mathematicorum"" 7144: 7087: 6561:The equilateral triangle tiling fills the plane. 6483:of 1 the triangle is equilateral if and only if 6064:{\textstyle {\tfrac {t^{3}-q^{3}}{t^{2}-q^{2}}}} 5991:{\displaystyle z={\frac {t^{2}+tq+q^{2}}{t+q}},} 3464: 2119:{\displaystyle r={\frac {r_{a}+r_{b}+r_{c}}{9}}} 697:{\displaystyle A={\frac {3{\sqrt {3}}}{4}}R^{2}} 7545: 7293: 7291: 7289: 5207:and the centroid of the equilateral triangle. 4535:being the vertices). There are numerous other 3834:{\displaystyle A={\frac {\sqrt {3}}{4}}a^{2}.} 2292:A triangle is equilateral if and only if, for 2227:of an equilateral triangle coincides with its 2218: 432:{\displaystyle A={\frac {\sqrt {3}}{4}}a^{2},} 8591: 7996: 7862: 7320:, 1996, Springer-Verlag, pp. 201 and 228–239. 6871:"An elementary proof of Blundon's inequality" 3434:{\displaystyle A={\frac {\sqrt {3}}{4}}a^{2}} 3391: 242:An equilateral triangle. It has equal sides ( 222:to each other and are each 60°. It is also a 7863:White, Steven F.; Calderón, Esthela (2008). 7424: 7388:"Another proof of the Erdős–Mordell Theorem" 7359: 7347:100 Great Problems of Elementary Mathematics 7275: 7273: 6978: 6193:{\displaystyle {\frac {\pi }{3{\sqrt {3}}}}} 3852:, the area of a triangle with any two sides 2239:A triangle is equilateral if any two of the 1586:{\displaystyle s={\frac {3{\sqrt {3}}}{2}}R} 755:The height of the center from each side, or 746:{\displaystyle A={\frac {h^{2}}{\sqrt {3}}}} 167:{\displaystyle {\tfrac {\sqrt {3}}{4}}a^{2}} 7619: 7617: 7476: 7286: 7083: 7081: 7079: 6616:are composed of equilateral triangles: the 6237:{\displaystyle {\frac {1}{12{\sqrt {3}}}},} 3469:The area of a triangle is half of one side 8598: 8584: 8003: 7989: 7570:(5). Taylor & Francis, Ltd.: 231–234. 6810: 3731:{\displaystyle h={\frac {\sqrt {3}}{2}}a.} 2954:in an equilateral triangle with distances 7895: 7270: 7088:Andreescu, Titu; Andrica, Dorian (2006). 6979:Alsina, Claudi; Nelsen, Roger B. (2009). 6731: 6597:constructed with equilateral triangles. 5140:{\displaystyle p^{4}+q^{4}+t^{4}=3\left,} 3956:{\displaystyle A={\frac {1}{2}}ab\sin C.} 3320: 2727:, respectively, define smaller triangles 630:{\displaystyle h={\frac {\sqrt {3}}{2}}a} 550:{\displaystyle r={\frac {\sqrt {3}}{6}}a} 460: 7899:Historical Dictionary of the Philippines 7745:Polytopes & their Incidence Matrices 7681: 7614: 7360:Svrtan, Dragutin; Veljan, Darko (2012). 7233:"The vertex-midpoint-centroid triangles" 7076: 7048: 7046: 6974: 6972: 6599: 6556: 3552: 3324: 2551: 2258:, or if its incenter coincides with its 2050:{\displaystyle 9R^{2}=a^{2}+b^{2}+c^{2}} 506:{\displaystyle R={\frac {a}{\sqrt {3}}}} 237: 8568:List of regular polytopes and compounds 7623: 7255: 7253: 7226: 7224: 7052: 6918: 4049:{\displaystyle {\tfrac {\sqrt {3}}{2}}} 233: 14: 9120: 7418: 7344: 2376:to the triangle's sides and distances 2286: 828:The radius of the inscribed circle is 299:{\displaystyle \alpha =\beta =\gamma } 8579: 7962: 7230: 7043: 6969: 6463:, then for either non-real cube root 5716:{\displaystyle q^{2}+qt+t^{2}=a^{2}.} 3843: 7738: 7250: 7221: 6777:Almost-equilateral Heronian triangle 6671:. The Platonic octahedron is also a 5504:of the circumcircle, with distances 2934:states that, for any interior point 867: 8605: 7741:"n-antiprism with winding number d" 7685:"Chapter 2: The Archimedean solids" 7519: 7385: 7205: 7159:Mathematical Association of America 6987:Mathematical Association of America 4234:inside any other regular polygon. 4172:of order 3 about its center, whose 4159: 3544:{\displaystyle A={\frac {1}{2}}ah.} 2547: 1953:Circumradius, inradius, and exradii 1503:{\displaystyle s^{2}=3{\sqrt {3}}T} 24: 7838:. Yale University Press. pp.  7450: 7444: 7323: 7310: 6565:Notably, the equilateral triangle 4453: 4424: 4395: 4217:(with vertices at the feet of the 4189: 3383: 2556:Visual proof of Viviani's theorem 210:, an equilateral triangle is also 25: 9144: 7955: 7835:Eero Saarinen: Shaping the Future 7434:International Journal of Geometry 6200:, is the largest of any triangle. 4307:{\displaystyle {\frac {R}{r}}=2.} 3606:, and the hypotenuse is the side 2173:{\displaystyle r_{a}=r_{b}=r_{c}} 1639:{\displaystyle A=B=C=60^{\circ }} 1459:{\displaystyle s^{2}=3r^{2}+12Rr} 819:{\displaystyle R={\frac {2h}{3}}} 352:{\displaystyle h_{a}=h_{b}=h_{c}} 226:, so it is also referred to as a 7902:. Scarecrow Press. p. 161. 7867:Culture and Customs of Nicaragua 7764: 7302:Challenging Problems in Geometry 5167:is the circumscribed radius and 4202:{\displaystyle \mathrm {D} _{3}} 3786:{\displaystyle {\frac {1}{2}}ah} 2183: 1343: 854:{\displaystyle r={\frac {h}{3}}} 583:{\displaystyle r={\frac {R}{2}}} 104: 99: 94: 45: 7916: 7889: 7856: 7825: 7783: 7758: 7747:. bendwavy.org (Anton Sherwood) 7732: 7675: 7539: 7513: 7470: 7405: 7379: 7353: 7349:. Dover Publ. pp. 379–380. 7338: 6378:If a triangle is placed in the 4221:), and the only triangle whose 3075:independent of the location of 1870: 1540:{\displaystyle s=3{\sqrt {3}}r} 7896:Guillermo, Artemio R. (2012). 7630:Geometries and Transformations 7491:10.1080/00029890.2008.11920581 7199: 7153:Methods for Euclidean Geometry 7138: 6912: 6862: 6804: 6758:It is a shape of a variety of 5187:is the distance between point 4360:; a stronger variant of it is 2906:form an equilateral triangle. 1925: 1912: 779:{\displaystyle {\frac {h}{3}}} 214:; that is, all three internal 13: 1: 7555:"Tilings by Regular Polygons" 7479:American Mathematical Monthly 7425:Meskhishvili, Mamuka (2021). 7208:"Notes on Euclidean Geometry" 7145:Owen, Byer; Felix, Lazebnik; 7092:Complex Numbers from A to...Z 6797: 6160:For an equilateral triangle: 4855:in the plane, with distances 4562:in the plane, with distances 3465:Using the Pythagorean theorem 2924:among all those with a given 2840:is a parallelogram, triangle 2316:in the plane, with distances 1196:respectively, is equilateral 383:, we can determine using the 7767:"Stella Polyhedral Glossary" 7096:(1st ed.). Boston, MA: 3014:from the sides and altitude 2271:For any triangle, the three 652:The area of the triangle is 32:Equilateral (disambiguation) 27:Shape with three equal sides 7: 7871:. Greenwood Press. p.  7682:Cromwell, Peter T. (1997). 7633:(1st ed.). Cambridge: 7335:46 (1), January 1973, 7–19, 6826:(1): 1–6 (Article No. 16). 6770: 4211:triangle with integer sides 2219:Coincident triangle centers 10: 9149: 8557: 7984: 7937:10.1177/001872088202400610 7635:Cambridge University Press 6884:(4): 1-3 (Paper No. 100). 6595:semi-regular tessellations 4468:{\displaystyle \angle CPA} 4439:{\displaystyle \angle BPC} 4410:{\displaystyle \angle APB} 3392:Derivation of area formula 2900:Morley's trisector theorem 599:(height) from any side is 29: 9014: 8960: 8900: 8844: 8783: 8774: 8666: 8618: 7345:Dörrie, Heinrich (1965). 7062:Gazeta Matematica Seria B 4178:dihedral group of order 6 1596: 1148:respectively), and where 644:, we can determine using 177: 128: 113: 87: 77: 63: 53: 44: 39: 7100:. pp. 70, 113–115. 7053:Pohoata, Cosmin (2010). 6995:10.5948/upo9781614442028 6630:analogue of the triangle 4384:to the points where the 4358:Erdős–Mordell inequality 3441:in terms of side length 3335:straightedge and compass 3068:{\displaystyle d+e+f=h,} 2918:isoperimetric inequality 1204: 465:{\displaystyle p=3a\,\!} 306:), and equal altitudes ( 7520:Dao, Thanh Oai (2015). 7451:De, Prithwijit (2008). 6753:flag of the Philippines 6476:{\displaystyle \omega } 6090:{\displaystyle t\neq q} 1798: 89:Coxeter–Dynkin diagrams 9133:Constructible polygons 7967:"Equilateral Triangle" 7803:Methuen & Co. LTD. 7801:(1 ed.). London: 7637:. pp. xv, 1–438. 7231:Cerin, Zvonko (2004). 7167:10.5860/choice.48-3331 6732:In culture and society 6722: 6692: 6661: 6605: 6562: 6549: 6477: 6457: 6430: 6403: 6382:with complex vertices 6370: 6297: 6270: 6238: 6194: 6147: 6091: 6065: 5992: 5917: 5897: 5874: 5854: 5831: 5808: 5785: 5762: 5739: 5717: 5653: 5652:{\displaystyle p=q+t,} 5618: 5598: 5578: 5558: 5538: 5518: 5498: 5475: 5453: 5369: 5284: 5264: 5244: 5224: 5201: 5181: 5161: 5141: 5004: 4909: 4889: 4869: 4849: 4827: 4676: 4656: 4636: 4616: 4596: 4576: 4556: 4529: 4509: 4489: 4469: 4440: 4411: 4378: 4350: 4330: 4308: 4275: 4255: 4203: 4150: 4050: 4017: 3957: 3906: 3886: 3866: 3835: 3787: 3760:into the area formula 3754: 3732: 3691: 3620: 3600: 3583: 3545: 3503: 3483: 3455: 3435: 3388: 3358: 3330: 3321:Geometric construction 3315:Van Schooten's theorem 3307: 3283: 3260: 3237: 3214: 3191: 3168: 3141: 3115: 3089: 3069: 3028: 3008: 2988: 2968: 2948: 2896: 2886: 2860: 2834: 2799: 2773: 2747: 2721: 2698: 2675: 2652: 2629: 2606: 2580: 2538: 2430: 2410: 2390: 2370: 2350: 2330: 2310: 2174: 2120: 2051: 1980: 1943: 1875: 1789: 1710: 1640: 1587: 1541: 1504: 1460: 1403: 1334: 1235: 1182: 1162: 1142: 1122: 1102: 1082: 1055: 1028: 998: 975: 952: 932: 912: 892: 855: 820: 780: 747: 698: 631: 584: 551: 507: 466: 433: 377: 360: 353: 300: 268: 168: 7643:10.1017/9781316216477 7460:Mathematical Spectrum 7106:10.1007/0-8176-4449-0 6792:Trilinear coordinates 6723: 6693: 6662: 6603: 6560: 6550: 6478: 6458: 6456:{\displaystyle z_{3}} 6431: 6429:{\displaystyle z_{2}} 6404: 6402:{\displaystyle z_{1}} 6371: 6298: 6296:{\displaystyle A_{2}} 6271: 6269:{\displaystyle A_{1}} 6239: 6195: 6148: 6092: 6066: 5993: 5918: 5898: 5875: 5855: 5832: 5809: 5786: 5763: 5740: 5718: 5654: 5619: 5599: 5579: 5559: 5539: 5519: 5499: 5476: 5454: 5370: 5285: 5265: 5245: 5225: 5202: 5182: 5162: 5142: 5005: 4910: 4890: 4870: 4850: 4828: 4677: 4657: 4637: 4617: 4597: 4577: 4557: 4537:triangle inequalities 4530: 4510: 4490: 4470: 4441: 4412: 4379: 4351: 4331: 4309: 4281:of any triangle, with 4276: 4256: 4204: 4151: 4051: 4018: 3958: 3907: 3887: 3867: 3836: 3788: 3755: 3733: 3692: 3621: 3601: 3556: 3546: 3504: 3484: 3456: 3436: 3387: 3359: 3328: 3308: 3284: 3261: 3238: 3215: 3192: 3169: 3142: 3116: 3090: 3070: 3029: 3009: 2989: 2969: 2949: 2887: 2861: 2835: 2800: 2774: 2748: 2722: 2699: 2676: 2653: 2630: 2607: 2581: 2555: 2539: 2431: 2411: 2391: 2371: 2351: 2331: 2311: 2175: 2121: 2052: 1981: 1944: 1876: 1790: 1711: 1641: 1588: 1542: 1505: 1461: 1404: 1335: 1236: 1234:{\displaystyle a=b=c} 1188:are the radii of the 1183: 1163: 1143: 1123: 1103: 1083: 1081:{\displaystyle r_{c}} 1056: 1054:{\displaystyle r_{b}} 1029: 1027:{\displaystyle r_{a}} 999: 976: 953: 933: 913: 893: 856: 821: 781: 748: 699: 632: 585: 552: 508: 467: 434: 378: 354: 301: 269: 267:{\displaystyle a=b=c} 241: 169: 8831:Nonagon/Enneagon (9) 8761:Tangential trapezoid 7563:Mathematics Magazine 7485:(October): 679–689. 7332:Mathematics Magazine 6989:. pp. 71, 155. 6931:Taylor & Francis 6922:Mathematics Magazine 6706: 6682: 6673:triangular antiprism 6648: 6612:. Three of the five 6487: 6467: 6440: 6413: 6386: 6310: 6280: 6253: 6209: 6168: 6101: 6075: 6002: 5927: 5907: 5884: 5864: 5841: 5818: 5795: 5772: 5749: 5729: 5662: 5628: 5608: 5588: 5568: 5548: 5528: 5508: 5485: 5465: 5378: 5294: 5274: 5254: 5234: 5214: 5191: 5171: 5151: 5013: 4919: 4899: 4879: 4859: 4839: 4686: 4666: 4646: 4626: 4606: 4586: 4566: 4546: 4519: 4499: 4479: 4450: 4421: 4392: 4368: 4340: 4320: 4285: 4265: 4245: 4184: 4060: 4029: 3969: 3916: 3896: 3876: 3856: 3797: 3764: 3744: 3701: 3633: 3610: 3590: 3513: 3493: 3473: 3445: 3400: 3348: 3297: 3270: 3247: 3224: 3201: 3178: 3155: 3125: 3105: 3079: 3038: 3018: 2998: 2978: 2958: 2938: 2870: 2844: 2833:{\displaystyle PGCH} 2815: 2783: 2757: 2731: 2708: 2685: 2662: 2639: 2616: 2593: 2564: 2440: 2420: 2400: 2380: 2360: 2340: 2320: 2300: 2131: 2062: 1992: 1979:{\displaystyle R=2r} 1961: 1891: 1807: 1721: 1651: 1605: 1552: 1515: 1471: 1415: 1352: 1246: 1213: 1172: 1152: 1132: 1112: 1092: 1065: 1038: 1011: 988: 965: 942: 922: 902: 876: 832: 792: 763: 715: 656: 603: 561: 523: 482: 476:circumscribed circle 445: 395: 367: 310: 278: 246: 234:Principal properties 200:equilateral triangle 137: 40:Equilateral triangle 8943:Megagon (1,000,000) 8711:Isosceles trapezoid 8552:pentagonal polytope 8451:Uniform 10-polytope 8011:Fundamental convex 7739:Klitzing, Richard. 7529:Forum Geometricorum 7413:Mathematical Circus 7395:Forum Geometricorum 7386:Lee, Hojoo (2001). 7369:Forum Geometricorum 7318:The Book of Numbers 7240:Forum Geometricorum 7161:. pp. 36, 39. 6721:{\displaystyle n=2} 6636:as well as uniform 5725:Moreover, if point 5290:from the vertices, 4915:from the vertices, 4362:Barrow's inequality 4170:rotational symmetry 4025:The sine of 60° is 3628:Pythagorean theorem 3291:triangle inequality 3140:{\displaystyle ABC} 2885:{\displaystyle ABC} 2859:{\displaystyle PHE} 2798:{\displaystyle PDG} 2772:{\displaystyle PFI} 2746:{\displaystyle PHE} 2579:{\displaystyle ABC} 2287:Points in the plane 2214:have equal lengths. 2207:have equal lengths. 2200:have equal lengths. 898:that has the sides 891:{\displaystyle ABC} 385:Pythagorean theorem 9128:Types of triangles 8913:Icositetragon (24) 8421:Uniform 9-polytope 8371:Uniform 8-polytope 8321:Uniform 7-polytope 8278:Uniform 6-polytope 8248:Uniform 5-polytope 8208:Uniform polychoron 8171:Uniform polyhedron 8019:in dimensions 2–10 7964:Weisstein, Eric W. 7805:pp. 120–121. 7625:Johnson, Norman W. 7281:Mathematical Plums 7206:Yiu, Paul (1998). 6782:Isosceles triangle 6718: 6688: 6660:{\displaystyle 2n} 6657: 6634:uniform antiprisms 6606: 6563: 6545: 6473: 6453: 6426: 6399: 6366: 6293: 6266: 6234: 6190: 6143: 6087: 6061: 6059: 5998:which also equals 5988: 5913: 5896:{\displaystyle PD} 5893: 5870: 5853:{\displaystyle DA} 5850: 5830:{\displaystyle DA} 5827: 5807:{\displaystyle PD} 5804: 5784:{\displaystyle PA} 5781: 5761:{\displaystyle BC} 5758: 5735: 5713: 5649: 5614: 5594: 5574: 5554: 5534: 5514: 5497:{\displaystyle BC} 5494: 5471: 5449: 5365: 5280: 5260: 5240: 5220: 5197: 5177: 5157: 5137: 5000: 4905: 4885: 4865: 4845: 4823: 4672: 4652: 4632: 4622:from the vertices 4612: 4592: 4572: 4552: 4525: 4505: 4485: 4465: 4436: 4407: 4374: 4346: 4326: 4304: 4271: 4251: 4239:Euler's inequality 4199: 4146: 4046: 4044: 4013: 3953: 3902: 3882: 3862: 3844:Using trigonometry 3831: 3783: 3750: 3728: 3687: 3616: 3596: 3584: 3541: 3499: 3479: 3451: 3431: 3389: 3354: 3331: 3303: 3282:{\displaystyle PC} 3279: 3259:{\displaystyle PB} 3256: 3236:{\displaystyle PA} 3233: 3213:{\displaystyle PC} 3210: 3190:{\displaystyle PB} 3187: 3167:{\displaystyle PA} 3164: 3137: 3111: 3085: 3065: 3024: 3004: 2984: 2964: 2944: 2910:Napoleon's theorem 2897: 2882: 2856: 2830: 2795: 2769: 2743: 2720:{\displaystyle CA} 2717: 2697:{\displaystyle BC} 2694: 2674:{\displaystyle AB} 2671: 2651:{\displaystyle HI} 2648: 2628:{\displaystyle FG} 2625: 2605:{\displaystyle DE} 2602: 2576: 2534: 2426: 2406: 2386: 2366: 2346: 2326: 2306: 2170: 2116: 2047: 1976: 1939: 1871: 1785: 1706: 1636: 1583: 1537: 1500: 1456: 1399: 1330: 1231: 1178: 1158: 1138: 1118: 1098: 1078: 1051: 1024: 994: 971: 948: 928: 908: 888: 851: 816: 776: 743: 694: 627: 580: 547: 515:The radius of the 503: 474:The radius of the 462: 429: 373: 361: 349: 296: 264: 208:Euclidean geometry 164: 152: 9115: 9114: 8956: 8955: 8933:Myriagon (10,000) 8918:Triacontagon (30) 8882:Heptadecagon (17) 8872:Pentadecagon (15) 8867:Tetradecagon (14) 8806:Quadrilateral (4) 8676:Antiparallelogram 8573: 8572: 8560:Polytope families 8017:uniform polytopes 7797:Regular Polytopes 7553:(November 1977). 7551:Shepard, Geoffrey 7147:Deirdre, Smeltzer 7115:978-0-8176-4449-9 7004:978-0-88385-342-9 6749:flag of Nicaragua 6691:{\displaystyle n} 6361: 6348: 6321: 6229: 6226: 6188: 6185: 6138: 6125: 6112: 6058: 5983: 5916:{\displaystyle y} 5873:{\displaystyle z} 5738:{\displaystyle D} 5617:{\displaystyle C} 5597:{\displaystyle B} 5577:{\displaystyle A} 5557:{\displaystyle t} 5537:{\displaystyle q} 5517:{\displaystyle p} 5481:on the minor arc 5474:{\displaystyle P} 5283:{\displaystyle t} 5263:{\displaystyle q} 5243:{\displaystyle p} 5223:{\displaystyle P} 5200:{\displaystyle P} 5180:{\displaystyle L} 5160:{\displaystyle R} 4908:{\displaystyle t} 4888:{\displaystyle q} 4868:{\displaystyle p} 4848:{\displaystyle P} 4675:{\displaystyle C} 4655:{\displaystyle B} 4635:{\displaystyle A} 4615:{\displaystyle t} 4595:{\displaystyle q} 4575:{\displaystyle p} 4555:{\displaystyle P} 4528:{\displaystyle C} 4508:{\displaystyle B} 4488:{\displaystyle A} 4475:cross the sides ( 4377:{\displaystyle P} 4349:{\displaystyle P} 4329:{\displaystyle P} 4296: 4274:{\displaystyle r} 4254:{\displaystyle R} 4223:Steiner inellipse 4134: 4130: 4113: 4109: 4098: 4094: 4077: 4043: 4039: 3986: 3933: 3905:{\displaystyle C} 3885:{\displaystyle b} 3865:{\displaystyle a} 3816: 3812: 3775: 3753:{\displaystyle h} 3720: 3716: 3649: 3619:{\displaystyle a} 3599:{\displaystyle a} 3530: 3502:{\displaystyle h} 3489:times the height 3482:{\displaystyle a} 3454:{\displaystyle a} 3419: 3415: 3396:The area formula 3357:{\displaystyle r} 3337:, because 3 is a 3306:{\displaystyle P} 3114:{\displaystyle P} 3099:Pompeiu's theorem 3088:{\displaystyle P} 3027:{\displaystyle h} 3007:{\displaystyle f} 2987:{\displaystyle e} 2967:{\displaystyle d} 2947:{\displaystyle P} 2932:Viviani's theorem 2916:A version of the 2436:to its vertices, 2429:{\displaystyle z} 2409:{\displaystyle y} 2389:{\displaystyle x} 2369:{\displaystyle r} 2349:{\displaystyle q} 2329:{\displaystyle p} 2309:{\displaystyle P} 2260:nine-point center 2114: 1936: 1910: 1906: 1868: 1865: 1783: 1770: 1754: 1738: 1704: 1578: 1572: 1532: 1495: 1383: 1328: 1316: 1283: 1270: 1257: 1181:{\displaystyle r} 1161:{\displaystyle R} 1141:{\displaystyle c} 1121:{\displaystyle b} 1101:{\displaystyle a} 997:{\displaystyle T} 974:{\displaystyle s} 951:{\displaystyle c} 931:{\displaystyle b} 911:{\displaystyle a} 868:Characterizations 849: 814: 774: 741: 740: 682: 676: 622: 618: 578: 542: 538: 501: 500: 441:The perimeter is 414: 410: 376:{\displaystyle a} 274:), equal angles ( 192: 191: 151: 147: 16:(Redirected from 9140: 8928:Chiliagon (1000) 8908:Icositrigon (23) 8887:Octadecagon (18) 8877:Hexadecagon (16) 8781: 8780: 8600: 8593: 8586: 8577: 8576: 8564:Regular polytope 8125: 8114: 8103: 8062: 8005: 7998: 7991: 7982: 7981: 7977: 7976: 7949: 7948: 7920: 7914: 7913: 7893: 7887: 7886: 7870: 7860: 7854: 7853: 7829: 7823: 7822: 7800: 7791:H. S. M. Coxeter 7787: 7781: 7780: 7778: 7777: 7762: 7756: 7755: 7753: 7752: 7736: 7730: 7729: 7687: 7679: 7673: 7672: 7621: 7612: 7611: 7559: 7547:Grünbaum, Branko 7543: 7537: 7536: 7526: 7517: 7511: 7510: 7474: 7468: 7467: 7457: 7448: 7442: 7441: 7431: 7422: 7416: 7409: 7403: 7402: 7392: 7383: 7377: 7376: 7366: 7357: 7351: 7350: 7342: 7336: 7327: 7321: 7314: 7308: 7307: 7305: 7295: 7284: 7277: 7268: 7267: 7265: 7257: 7248: 7247: 7237: 7228: 7219: 7218: 7212: 7203: 7197: 7196: 7156: 7142: 7136: 7135: 7095: 7085: 7074: 7073: 7059: 7050: 7041: 7040: 6976: 6967: 6966: 6916: 6910: 6909: 6875: 6866: 6860: 6859: 6817: 6808: 6762:, including the 6727: 6725: 6724: 6719: 6697: 6695: 6694: 6689: 6666: 6664: 6663: 6658: 6571:hexagonal tiling 6554: 6552: 6551: 6546: 6538: 6537: 6528: 6527: 6515: 6514: 6499: 6498: 6482: 6480: 6479: 6474: 6462: 6460: 6459: 6454: 6452: 6451: 6435: 6433: 6432: 6427: 6425: 6424: 6408: 6406: 6405: 6400: 6398: 6397: 6375: 6373: 6372: 6367: 6362: 6354: 6349: 6347: 6346: 6337: 6336: 6327: 6322: 6314: 6302: 6300: 6299: 6294: 6292: 6291: 6275: 6273: 6272: 6267: 6265: 6264: 6243: 6241: 6240: 6235: 6230: 6228: 6227: 6222: 6213: 6199: 6197: 6196: 6191: 6189: 6187: 6186: 6181: 6172: 6152: 6150: 6149: 6144: 6139: 6131: 6126: 6118: 6113: 6105: 6096: 6094: 6093: 6088: 6070: 6068: 6067: 6062: 6060: 6057: 6056: 6055: 6043: 6042: 6032: 6031: 6030: 6018: 6017: 6007: 5997: 5995: 5994: 5989: 5984: 5982: 5971: 5970: 5969: 5948: 5947: 5937: 5922: 5920: 5919: 5914: 5902: 5900: 5899: 5894: 5879: 5877: 5876: 5871: 5859: 5857: 5856: 5851: 5836: 5834: 5833: 5828: 5813: 5811: 5810: 5805: 5790: 5788: 5787: 5782: 5767: 5765: 5764: 5759: 5744: 5742: 5741: 5736: 5722: 5720: 5719: 5714: 5709: 5708: 5696: 5695: 5674: 5673: 5658: 5656: 5655: 5650: 5623: 5621: 5620: 5615: 5603: 5601: 5600: 5595: 5583: 5581: 5580: 5575: 5563: 5561: 5560: 5555: 5543: 5541: 5540: 5535: 5523: 5521: 5520: 5515: 5503: 5501: 5500: 5495: 5480: 5478: 5477: 5472: 5458: 5456: 5455: 5450: 5445: 5444: 5429: 5425: 5424: 5423: 5411: 5410: 5398: 5397: 5374: 5372: 5371: 5366: 5361: 5360: 5345: 5341: 5340: 5339: 5327: 5326: 5314: 5313: 5289: 5287: 5286: 5281: 5269: 5267: 5266: 5261: 5249: 5247: 5246: 5241: 5229: 5227: 5226: 5221: 5206: 5204: 5203: 5198: 5186: 5184: 5183: 5178: 5166: 5164: 5163: 5158: 5146: 5144: 5143: 5138: 5133: 5129: 5128: 5127: 5118: 5117: 5102: 5101: 5096: 5092: 5091: 5090: 5078: 5077: 5051: 5050: 5038: 5037: 5025: 5024: 5009: 5007: 5006: 5001: 4996: 4992: 4991: 4990: 4978: 4977: 4957: 4956: 4944: 4943: 4931: 4930: 4914: 4912: 4911: 4906: 4894: 4892: 4891: 4886: 4874: 4872: 4871: 4866: 4854: 4852: 4851: 4846: 4832: 4830: 4829: 4824: 4819: 4818: 4813: 4809: 4808: 4807: 4795: 4794: 4782: 4781: 4769: 4768: 4750: 4746: 4745: 4744: 4732: 4731: 4719: 4718: 4706: 4705: 4681: 4679: 4678: 4673: 4661: 4659: 4658: 4653: 4641: 4639: 4638: 4633: 4621: 4619: 4618: 4613: 4601: 4599: 4598: 4593: 4581: 4579: 4578: 4573: 4561: 4559: 4558: 4553: 4534: 4532: 4531: 4526: 4514: 4512: 4511: 4506: 4494: 4492: 4491: 4486: 4474: 4472: 4471: 4466: 4445: 4443: 4442: 4437: 4416: 4414: 4413: 4408: 4383: 4381: 4380: 4375: 4355: 4353: 4352: 4347: 4335: 4333: 4332: 4327: 4313: 4311: 4310: 4305: 4297: 4289: 4280: 4278: 4277: 4272: 4261:to the inradius 4260: 4258: 4257: 4252: 4208: 4206: 4205: 4200: 4198: 4197: 4192: 4160:Other properties 4155: 4153: 4152: 4147: 4145: 4144: 4135: 4126: 4125: 4114: 4105: 4104: 4099: 4090: 4089: 4078: 4070: 4055: 4053: 4052: 4047: 4045: 4035: 4034: 4022: 4020: 4019: 4014: 4009: 4008: 3987: 3979: 3962: 3960: 3959: 3954: 3934: 3926: 3912:between them is 3911: 3909: 3908: 3903: 3891: 3889: 3888: 3883: 3871: 3869: 3868: 3863: 3840: 3838: 3837: 3832: 3827: 3826: 3817: 3808: 3807: 3792: 3790: 3789: 3784: 3776: 3768: 3759: 3757: 3756: 3751: 3737: 3735: 3734: 3729: 3721: 3712: 3711: 3696: 3694: 3693: 3688: 3686: 3685: 3673: 3672: 3660: 3659: 3654: 3650: 3642: 3625: 3623: 3622: 3617: 3605: 3603: 3602: 3597: 3581: 3579: 3578: 3567: 3565: 3564: 3550: 3548: 3547: 3542: 3531: 3523: 3509:from that side: 3508: 3506: 3505: 3500: 3488: 3486: 3485: 3480: 3460: 3458: 3457: 3452: 3440: 3438: 3437: 3432: 3430: 3429: 3420: 3411: 3410: 3363: 3361: 3360: 3355: 3312: 3310: 3309: 3304: 3288: 3286: 3285: 3280: 3265: 3263: 3262: 3257: 3242: 3240: 3239: 3234: 3219: 3217: 3216: 3211: 3196: 3194: 3193: 3188: 3173: 3171: 3170: 3165: 3146: 3144: 3143: 3138: 3120: 3118: 3117: 3112: 3101:states that, if 3094: 3092: 3091: 3086: 3074: 3072: 3071: 3066: 3033: 3031: 3030: 3025: 3013: 3011: 3010: 3005: 2993: 2991: 2990: 2985: 2973: 2971: 2970: 2965: 2953: 2951: 2950: 2945: 2928:is equilateral. 2904:angle trisectors 2891: 2889: 2888: 2883: 2865: 2863: 2862: 2857: 2839: 2837: 2836: 2831: 2804: 2802: 2801: 2796: 2778: 2776: 2775: 2770: 2752: 2750: 2749: 2744: 2726: 2724: 2723: 2718: 2703: 2701: 2700: 2695: 2680: 2678: 2677: 2672: 2657: 2655: 2654: 2649: 2634: 2632: 2631: 2626: 2611: 2609: 2608: 2603: 2585: 2583: 2582: 2577: 2548:Notable theorems 2543: 2541: 2540: 2535: 2530: 2529: 2517: 2516: 2504: 2503: 2491: 2487: 2486: 2485: 2473: 2472: 2460: 2459: 2435: 2433: 2432: 2427: 2415: 2413: 2412: 2407: 2395: 2393: 2392: 2387: 2375: 2373: 2372: 2367: 2355: 2353: 2352: 2347: 2335: 2333: 2332: 2327: 2315: 2313: 2312: 2307: 2179: 2177: 2176: 2171: 2169: 2168: 2156: 2155: 2143: 2142: 2125: 2123: 2122: 2117: 2115: 2110: 2109: 2108: 2096: 2095: 2083: 2082: 2072: 2056: 2054: 2053: 2048: 2046: 2045: 2033: 2032: 2020: 2019: 2007: 2006: 1985: 1983: 1982: 1977: 1948: 1946: 1945: 1940: 1938: 1937: 1929: 1911: 1902: 1901: 1880: 1878: 1877: 1872: 1869: 1867: 1866: 1861: 1855: 1854: 1853: 1841: 1840: 1828: 1827: 1817: 1794: 1792: 1791: 1786: 1784: 1776: 1771: 1763: 1755: 1747: 1739: 1731: 1715: 1713: 1712: 1707: 1705: 1697: 1692: 1678: 1664: 1645: 1643: 1642: 1637: 1635: 1634: 1592: 1590: 1589: 1584: 1579: 1574: 1573: 1568: 1562: 1546: 1544: 1543: 1538: 1533: 1528: 1509: 1507: 1506: 1501: 1496: 1491: 1483: 1482: 1465: 1463: 1462: 1457: 1443: 1442: 1427: 1426: 1408: 1406: 1405: 1400: 1395: 1391: 1384: 1379: 1339: 1337: 1336: 1331: 1329: 1327: 1315: 1314: 1290: 1289: 1284: 1276: 1271: 1263: 1258: 1250: 1240: 1238: 1237: 1232: 1187: 1185: 1184: 1179: 1167: 1165: 1164: 1159: 1147: 1145: 1144: 1139: 1127: 1125: 1124: 1119: 1107: 1105: 1104: 1099: 1087: 1085: 1084: 1079: 1077: 1076: 1060: 1058: 1057: 1052: 1050: 1049: 1033: 1031: 1030: 1025: 1023: 1022: 1003: 1001: 1000: 995: 980: 978: 977: 972: 957: 955: 954: 949: 937: 935: 934: 929: 917: 915: 914: 909: 897: 895: 894: 889: 860: 858: 857: 852: 850: 842: 825: 823: 822: 817: 815: 810: 802: 785: 783: 782: 777: 775: 767: 752: 750: 749: 744: 742: 736: 735: 734: 725: 703: 701: 700: 695: 693: 692: 683: 678: 677: 672: 666: 636: 634: 633: 628: 623: 614: 613: 589: 587: 586: 581: 579: 571: 556: 554: 553: 548: 543: 534: 533: 517:inscribed circle 512: 510: 509: 504: 502: 496: 492: 471: 469: 468: 463: 438: 436: 435: 430: 425: 424: 415: 406: 405: 382: 380: 379: 374: 358: 356: 355: 350: 348: 347: 335: 334: 322: 321: 305: 303: 302: 297: 273: 271: 270: 265: 228:regular triangle 173: 171: 170: 165: 163: 162: 153: 143: 142: 109: 108: 107: 103: 102: 98: 97: 49: 37: 36: 21: 18:Regular triangle 9148: 9147: 9143: 9142: 9141: 9139: 9138: 9137: 9118: 9117: 9116: 9111: 9010: 8964: 8952: 8896: 8862:Tridecagon (13) 8852:Hendecagon (11) 8840: 8776: 8770: 8741:Right trapezoid 8662: 8614: 8604: 8574: 8543: 8536: 8529: 8412: 8405: 8398: 8362: 8355: 8348: 8312: 8305: 8139:Regular polygon 8132: 8123: 8116: 8112: 8105: 8101: 8092: 8083: 8076: 8072: 8060: 8054: 8050: 8038: 8020: 8009: 7958: 7953: 7952: 7921: 7917: 7910: 7894: 7890: 7883: 7861: 7857: 7850: 7830: 7826: 7788: 7784: 7775: 7773: 7763: 7759: 7750: 7748: 7737: 7733: 7702: 7680: 7676: 7653: 7622: 7615: 7576:10.2307/2689529 7557: 7544: 7540: 7524: 7518: 7514: 7475: 7471: 7455: 7449: 7445: 7429: 7423: 7419: 7410: 7406: 7390: 7384: 7380: 7364: 7358: 7354: 7343: 7339: 7328: 7324: 7315: 7311: 7296: 7287: 7278: 7271: 7263: 7259: 7258: 7251: 7235: 7229: 7222: 7217:(Course Notes). 7210: 7204: 7200: 7177: 7143: 7139: 7116: 7086: 7077: 7057: 7051: 7044: 7005: 6977: 6970: 6939:10.2307/2687913 6917: 6913: 6873: 6867: 6863: 6815: 6809: 6805: 6800: 6773: 6734: 6707: 6704: 6703: 6683: 6680: 6679: 6649: 6646: 6645: 6638:star antiprisms 6614:Platonic solids 6533: 6529: 6523: 6519: 6510: 6506: 6494: 6490: 6488: 6485: 6484: 6468: 6465: 6464: 6447: 6443: 6441: 6438: 6437: 6420: 6416: 6414: 6411: 6410: 6393: 6389: 6387: 6384: 6383: 6353: 6342: 6338: 6332: 6328: 6326: 6313: 6311: 6308: 6307: 6287: 6283: 6281: 6278: 6277: 6260: 6256: 6254: 6251: 6250: 6221: 6217: 6212: 6210: 6207: 6206: 6180: 6176: 6171: 6169: 6166: 6165: 6130: 6117: 6104: 6102: 6099: 6098: 6076: 6073: 6072: 6051: 6047: 6038: 6034: 6033: 6026: 6022: 6013: 6009: 6008: 6005: 6003: 6000: 5999: 5972: 5965: 5961: 5943: 5939: 5938: 5936: 5928: 5925: 5924: 5908: 5905: 5904: 5885: 5882: 5881: 5865: 5862: 5861: 5842: 5839: 5838: 5819: 5816: 5815: 5796: 5793: 5792: 5773: 5770: 5769: 5750: 5747: 5746: 5730: 5727: 5726: 5704: 5700: 5691: 5687: 5669: 5665: 5663: 5660: 5659: 5629: 5626: 5625: 5624:, respectively 5609: 5606: 5605: 5589: 5586: 5585: 5569: 5566: 5565: 5549: 5546: 5545: 5529: 5526: 5525: 5509: 5506: 5505: 5486: 5483: 5482: 5466: 5463: 5462: 5440: 5436: 5419: 5415: 5406: 5402: 5393: 5389: 5388: 5384: 5379: 5376: 5375: 5356: 5352: 5335: 5331: 5322: 5318: 5309: 5305: 5304: 5300: 5295: 5292: 5291: 5275: 5272: 5271: 5255: 5252: 5251: 5235: 5232: 5231: 5215: 5212: 5211: 5192: 5189: 5188: 5172: 5169: 5168: 5152: 5149: 5148: 5123: 5119: 5113: 5109: 5097: 5086: 5082: 5073: 5069: 5068: 5064: 5063: 5062: 5058: 5046: 5042: 5033: 5029: 5020: 5016: 5014: 5011: 5010: 4986: 4982: 4973: 4969: 4968: 4964: 4952: 4948: 4939: 4935: 4926: 4922: 4920: 4917: 4916: 4900: 4897: 4896: 4880: 4877: 4876: 4860: 4857: 4856: 4840: 4837: 4836: 4814: 4803: 4799: 4790: 4786: 4777: 4773: 4764: 4760: 4759: 4755: 4754: 4740: 4736: 4727: 4723: 4714: 4710: 4701: 4697: 4696: 4692: 4687: 4684: 4683: 4667: 4664: 4663: 4647: 4644: 4643: 4627: 4624: 4623: 4607: 4604: 4603: 4587: 4584: 4583: 4567: 4564: 4563: 4547: 4544: 4543: 4520: 4517: 4516: 4500: 4497: 4496: 4480: 4477: 4476: 4451: 4448: 4447: 4422: 4419: 4418: 4393: 4390: 4389: 4386:angle bisectors 4369: 4366: 4365: 4341: 4338: 4337: 4321: 4318: 4317: 4288: 4286: 4283: 4282: 4266: 4263: 4262: 4246: 4243: 4242: 4215:orthic triangle 4193: 4188: 4187: 4185: 4182: 4181: 4162: 4140: 4136: 4124: 4103: 4088: 4069: 4061: 4058: 4057: 4032: 4030: 4027: 4026: 4004: 4000: 3978: 3970: 3967: 3966: 3925: 3917: 3914: 3913: 3897: 3894: 3893: 3892:, and an angle 3877: 3874: 3873: 3857: 3854: 3853: 3846: 3822: 3818: 3806: 3798: 3795: 3794: 3767: 3765: 3762: 3761: 3745: 3742: 3741: 3710: 3702: 3699: 3698: 3681: 3677: 3668: 3664: 3655: 3641: 3637: 3636: 3634: 3631: 3630: 3611: 3608: 3607: 3591: 3588: 3587: 3576: 3574: 3573: 3562: 3560: 3558: 3522: 3514: 3511: 3510: 3494: 3491: 3490: 3474: 3471: 3470: 3467: 3446: 3443: 3442: 3425: 3421: 3409: 3401: 3398: 3397: 3394: 3349: 3346: 3345: 3323: 3298: 3295: 3294: 3271: 3268: 3267: 3248: 3245: 3244: 3225: 3222: 3221: 3202: 3199: 3198: 3179: 3176: 3175: 3156: 3153: 3152: 3147:but not on its 3126: 3123: 3122: 3106: 3103: 3102: 3080: 3077: 3076: 3039: 3036: 3035: 3019: 3016: 3015: 2999: 2996: 2995: 2979: 2976: 2975: 2959: 2956: 2955: 2939: 2936: 2935: 2895: 2871: 2868: 2867: 2845: 2842: 2841: 2816: 2813: 2812: 2784: 2781: 2780: 2758: 2755: 2754: 2732: 2729: 2728: 2709: 2706: 2705: 2686: 2683: 2682: 2663: 2660: 2659: 2640: 2637: 2636: 2617: 2614: 2613: 2594: 2591: 2590: 2565: 2562: 2561: 2550: 2525: 2521: 2512: 2508: 2499: 2495: 2481: 2477: 2468: 2464: 2455: 2451: 2450: 2446: 2441: 2438: 2437: 2421: 2418: 2417: 2401: 2398: 2397: 2381: 2378: 2377: 2361: 2358: 2357: 2341: 2338: 2337: 2321: 2318: 2317: 2301: 2298: 2297: 2289: 2269: 2247:, centroid, or 2225:triangle center 2221: 2212:angle bisectors 2188:Three kinds of 2186: 2164: 2160: 2151: 2147: 2138: 2134: 2132: 2129: 2128: 2104: 2100: 2091: 2087: 2078: 2074: 2073: 2071: 2063: 2060: 2059: 2041: 2037: 2028: 2024: 2015: 2011: 2002: 1998: 1993: 1990: 1989: 1986:(Chapple-Euler) 1962: 1959: 1958: 1955: 1928: 1924: 1900: 1892: 1889: 1888: 1860: 1856: 1849: 1845: 1836: 1832: 1823: 1819: 1818: 1816: 1808: 1805: 1804: 1801: 1775: 1762: 1746: 1730: 1722: 1719: 1718: 1696: 1688: 1674: 1660: 1652: 1649: 1648: 1630: 1626: 1606: 1603: 1602: 1599: 1567: 1563: 1561: 1553: 1550: 1549: 1527: 1516: 1513: 1512: 1490: 1478: 1474: 1472: 1469: 1468: 1438: 1434: 1422: 1418: 1416: 1413: 1412: 1378: 1374: 1370: 1353: 1350: 1349: 1346: 1317: 1310: 1306: 1288: 1275: 1262: 1249: 1247: 1244: 1243: 1214: 1211: 1210: 1207: 1173: 1170: 1169: 1153: 1150: 1149: 1133: 1130: 1129: 1113: 1110: 1109: 1093: 1090: 1089: 1072: 1068: 1066: 1063: 1062: 1045: 1041: 1039: 1036: 1035: 1018: 1014: 1012: 1009: 1008: 989: 986: 985: 966: 963: 962: 943: 940: 939: 923: 920: 919: 903: 900: 899: 877: 874: 873: 870: 841: 833: 830: 829: 803: 801: 793: 790: 789: 766: 764: 761: 760: 730: 726: 724: 716: 713: 712: 688: 684: 671: 667: 665: 657: 654: 653: 612: 604: 601: 600: 570: 562: 559: 558: 532: 524: 521: 520: 491: 483: 480: 479: 446: 443: 442: 420: 416: 404: 396: 393: 392: 368: 365: 364: 343: 339: 330: 326: 317: 313: 311: 308: 307: 279: 276: 275: 247: 244: 243: 236: 224:regular polygon 158: 154: 140: 138: 135: 134: 123: 105: 100: 95: 93: 79:Schläfli symbol 58:Regular polygon 35: 28: 23: 22: 15: 12: 11: 5: 9146: 9136: 9135: 9130: 9113: 9112: 9110: 9109: 9104: 9099: 9094: 9089: 9084: 9079: 9074: 9069: 9067:Pseudotriangle 9064: 9059: 9054: 9049: 9044: 9039: 9034: 9029: 9024: 9018: 9016: 9012: 9011: 9009: 9008: 9003: 8998: 8993: 8988: 8983: 8978: 8973: 8967: 8965: 8958: 8957: 8954: 8953: 8951: 8950: 8945: 8940: 8935: 8930: 8925: 8920: 8915: 8910: 8904: 8902: 8898: 8897: 8895: 8894: 8889: 8884: 8879: 8874: 8869: 8864: 8859: 8857:Dodecagon (12) 8854: 8848: 8846: 8842: 8841: 8839: 8838: 8833: 8828: 8823: 8818: 8813: 8808: 8803: 8798: 8793: 8787: 8785: 8778: 8772: 8771: 8769: 8768: 8763: 8758: 8753: 8748: 8743: 8738: 8733: 8728: 8723: 8718: 8713: 8708: 8703: 8698: 8693: 8688: 8683: 8678: 8672: 8670: 8668:Quadrilaterals 8664: 8663: 8661: 8660: 8655: 8650: 8645: 8640: 8635: 8630: 8624: 8622: 8616: 8615: 8603: 8602: 8595: 8588: 8580: 8571: 8570: 8555: 8554: 8545: 8541: 8534: 8527: 8523: 8514: 8497: 8488: 8477: 8476: 8474: 8472: 8467: 8458: 8453: 8447: 8446: 8444: 8442: 8437: 8428: 8423: 8417: 8416: 8414: 8410: 8403: 8396: 8392: 8387: 8378: 8373: 8367: 8366: 8364: 8360: 8353: 8346: 8342: 8337: 8328: 8323: 8317: 8316: 8314: 8310: 8303: 8299: 8294: 8285: 8280: 8274: 8273: 8271: 8269: 8264: 8255: 8250: 8244: 8243: 8234: 8229: 8224: 8215: 8210: 8204: 8203: 8194: 8192: 8187: 8178: 8173: 8167: 8166: 8161: 8156: 8151: 8146: 8141: 8135: 8134: 8130: 8126: 8121: 8110: 8099: 8090: 8081: 8074: 8068: 8058: 8052: 8046: 8040: 8034: 8028: 8022: 8021: 8010: 8008: 8007: 8000: 7993: 7985: 7980: 7979: 7978: 7957: 7956:External links 7954: 7951: 7950: 7931:(6): 737–742. 7915: 7909:978-0810872462 7908: 7888: 7882:978-0313339943 7881: 7855: 7849:978-0972488129 7848: 7824: 7782: 7765:Webb, Robert. 7757: 7731: 7701:978-0521664059 7700: 7674: 7652:978-1107103405 7651: 7613: 7538: 7512: 7469: 7443: 7417: 7415:, 1979, p. 65. 7404: 7378: 7352: 7337: 7322: 7309: 7285: 7269: 7249: 7220: 7198: 7175: 7137: 7114: 7075: 7064:(3): 121–123. 7042: 7003: 6968: 6911: 6861: 6802: 6801: 6799: 6796: 6795: 6794: 6789: 6784: 6779: 6772: 6769: 6768: 6767: 6756: 6745: 6733: 6730: 6717: 6714: 6711: 6687: 6656: 6653: 6544: 6541: 6536: 6532: 6526: 6522: 6518: 6513: 6509: 6505: 6502: 6497: 6493: 6472: 6450: 6446: 6423: 6419: 6396: 6392: 6365: 6360: 6357: 6352: 6345: 6341: 6335: 6331: 6325: 6320: 6317: 6305: 6304: 6290: 6286: 6263: 6259: 6246: 6245: 6233: 6225: 6220: 6216: 6202: 6201: 6184: 6179: 6175: 6155:optic equation 6142: 6137: 6134: 6129: 6124: 6121: 6116: 6111: 6108: 6086: 6083: 6080: 6054: 6050: 6046: 6041: 6037: 6029: 6025: 6021: 6016: 6012: 5987: 5981: 5978: 5975: 5968: 5964: 5960: 5957: 5954: 5951: 5946: 5942: 5935: 5932: 5912: 5903:having length 5892: 5889: 5869: 5860:having length 5849: 5846: 5826: 5823: 5803: 5800: 5791:into segments 5780: 5777: 5757: 5754: 5734: 5712: 5707: 5703: 5699: 5694: 5690: 5686: 5683: 5680: 5677: 5672: 5668: 5648: 5645: 5642: 5639: 5636: 5633: 5613: 5593: 5573: 5553: 5533: 5513: 5493: 5490: 5470: 5461:For any point 5448: 5443: 5439: 5435: 5432: 5428: 5422: 5418: 5414: 5409: 5405: 5401: 5396: 5392: 5387: 5383: 5364: 5359: 5355: 5351: 5348: 5344: 5338: 5334: 5330: 5325: 5321: 5317: 5312: 5308: 5303: 5299: 5279: 5259: 5239: 5219: 5210:For any point 5196: 5176: 5156: 5136: 5132: 5126: 5122: 5116: 5112: 5108: 5105: 5100: 5095: 5089: 5085: 5081: 5076: 5072: 5067: 5061: 5057: 5054: 5049: 5045: 5041: 5036: 5032: 5028: 5023: 5019: 4999: 4995: 4989: 4985: 4981: 4976: 4972: 4967: 4963: 4960: 4955: 4951: 4947: 4942: 4938: 4934: 4929: 4925: 4904: 4884: 4864: 4844: 4835:For any point 4822: 4817: 4812: 4806: 4802: 4798: 4793: 4789: 4785: 4780: 4776: 4772: 4767: 4763: 4758: 4753: 4749: 4743: 4739: 4735: 4730: 4726: 4722: 4717: 4713: 4709: 4704: 4700: 4695: 4691: 4682:respectively, 4671: 4651: 4631: 4611: 4591: 4571: 4551: 4542:For any point 4524: 4504: 4484: 4464: 4461: 4458: 4455: 4435: 4432: 4429: 4426: 4406: 4403: 4400: 4397: 4373: 4345: 4325: 4316:Given a point 4303: 4300: 4295: 4292: 4270: 4250: 4196: 4191: 4174:symmetry group 4161: 4158: 4143: 4139: 4133: 4129: 4123: 4120: 4117: 4112: 4108: 4102: 4097: 4093: 4087: 4084: 4081: 4076: 4073: 4068: 4065: 4042: 4038: 4012: 4007: 4003: 3999: 3996: 3993: 3990: 3985: 3982: 3977: 3974: 3952: 3949: 3946: 3943: 3940: 3937: 3932: 3929: 3924: 3921: 3901: 3881: 3861: 3845: 3842: 3830: 3825: 3821: 3815: 3811: 3805: 3802: 3782: 3779: 3774: 3771: 3749: 3727: 3724: 3719: 3715: 3709: 3706: 3684: 3680: 3676: 3671: 3667: 3663: 3658: 3653: 3648: 3645: 3640: 3615: 3595: 3540: 3537: 3534: 3529: 3526: 3521: 3518: 3498: 3478: 3466: 3463: 3450: 3428: 3424: 3418: 3414: 3408: 3405: 3393: 3390: 3353: 3322: 3319: 3302: 3278: 3275: 3255: 3252: 3232: 3229: 3209: 3206: 3186: 3183: 3163: 3160: 3136: 3133: 3130: 3110: 3084: 3064: 3061: 3058: 3055: 3052: 3049: 3046: 3043: 3023: 3003: 2983: 2963: 2943: 2894: 2893: 2881: 2878: 2875: 2855: 2852: 2849: 2829: 2826: 2823: 2820: 2809: 2806: 2794: 2791: 2788: 2768: 2765: 2762: 2742: 2739: 2736: 2716: 2713: 2693: 2690: 2670: 2667: 2647: 2644: 2624: 2621: 2601: 2598: 2587: 2575: 2572: 2569: 2557: 2549: 2546: 2545: 2544: 2533: 2528: 2524: 2520: 2515: 2511: 2507: 2502: 2498: 2494: 2490: 2484: 2480: 2476: 2471: 2467: 2463: 2458: 2454: 2449: 2445: 2425: 2405: 2385: 2365: 2345: 2325: 2305: 2288: 2285: 2284: 2283: 2280: 2268: 2265: 2264: 2263: 2252: 2220: 2217: 2216: 2215: 2208: 2201: 2185: 2182: 2181: 2180: 2167: 2163: 2159: 2154: 2150: 2146: 2141: 2137: 2126: 2113: 2107: 2103: 2099: 2094: 2090: 2086: 2081: 2077: 2070: 2067: 2057: 2044: 2040: 2036: 2031: 2027: 2023: 2018: 2014: 2010: 2005: 2001: 1997: 1987: 1975: 1972: 1969: 1966: 1954: 1951: 1950: 1949: 1935: 1932: 1927: 1923: 1920: 1917: 1914: 1909: 1905: 1899: 1896: 1886: 1864: 1859: 1852: 1848: 1844: 1839: 1835: 1831: 1826: 1822: 1815: 1812: 1800: 1797: 1796: 1795: 1782: 1779: 1774: 1769: 1766: 1761: 1758: 1753: 1750: 1745: 1742: 1737: 1734: 1729: 1726: 1716: 1703: 1700: 1695: 1691: 1687: 1684: 1681: 1677: 1673: 1670: 1667: 1663: 1659: 1656: 1646: 1633: 1629: 1625: 1622: 1619: 1616: 1613: 1610: 1598: 1595: 1594: 1593: 1582: 1577: 1571: 1566: 1560: 1557: 1547: 1536: 1531: 1526: 1523: 1520: 1510: 1499: 1494: 1489: 1486: 1481: 1477: 1466: 1455: 1452: 1449: 1446: 1441: 1437: 1433: 1430: 1425: 1421: 1410: 1398: 1394: 1390: 1387: 1382: 1377: 1373: 1369: 1366: 1363: 1360: 1357: 1345: 1342: 1341: 1340: 1326: 1323: 1320: 1313: 1309: 1305: 1302: 1299: 1296: 1293: 1287: 1282: 1279: 1274: 1269: 1266: 1261: 1256: 1253: 1241: 1230: 1227: 1224: 1221: 1218: 1206: 1203: 1198:if and only if 1177: 1157: 1137: 1117: 1097: 1075: 1071: 1048: 1044: 1021: 1017: 993: 970: 947: 927: 907: 887: 884: 881: 869: 866: 862: 861: 848: 845: 840: 837: 826: 813: 809: 806: 800: 797: 786: 773: 770: 753: 739: 733: 729: 723: 720: 705: 704: 691: 687: 681: 675: 670: 664: 661: 638: 637: 626: 621: 617: 611: 608: 593: 590: 577: 574: 569: 566: 546: 541: 537: 531: 528: 513: 499: 495: 490: 487: 472: 459: 456: 453: 450: 439: 428: 423: 419: 413: 409: 403: 400: 372: 346: 342: 338: 333: 329: 325: 320: 316: 295: 292: 289: 286: 283: 263: 260: 257: 254: 251: 235: 232: 190: 189: 186: 179:Internal angle 175: 174: 161: 157: 150: 146: 132: 126: 125: 121: 117: 115:Symmetry group 111: 110: 91: 85: 84: 81: 75: 74: 71: 61: 60: 55: 51: 50: 42: 41: 26: 9: 6: 4: 3: 2: 9145: 9134: 9131: 9129: 9126: 9125: 9123: 9108: 9107:Weakly simple 9105: 9103: 9100: 9098: 9095: 9093: 9090: 9088: 9085: 9083: 9080: 9078: 9075: 9073: 9070: 9068: 9065: 9063: 9060: 9058: 9055: 9053: 9050: 9048: 9047:Infinite skew 9045: 9043: 9040: 9038: 9035: 9033: 9030: 9028: 9025: 9023: 9020: 9019: 9017: 9013: 9007: 9004: 9002: 8999: 8997: 8994: 8992: 8989: 8987: 8984: 8982: 8979: 8977: 8974: 8972: 8969: 8968: 8966: 8963: 8962:Star polygons 8959: 8949: 8948:Apeirogon (∞) 8946: 8944: 8941: 8939: 8936: 8934: 8931: 8929: 8926: 8924: 8921: 8919: 8916: 8914: 8911: 8909: 8906: 8905: 8903: 8899: 8893: 8892:Icosagon (20) 8890: 8888: 8885: 8883: 8880: 8878: 8875: 8873: 8870: 8868: 8865: 8863: 8860: 8858: 8855: 8853: 8850: 8849: 8847: 8843: 8837: 8834: 8832: 8829: 8827: 8824: 8822: 8819: 8817: 8814: 8812: 8809: 8807: 8804: 8802: 8799: 8797: 8794: 8792: 8789: 8788: 8786: 8782: 8779: 8773: 8767: 8764: 8762: 8759: 8757: 8754: 8752: 8749: 8747: 8744: 8742: 8739: 8737: 8734: 8732: 8729: 8727: 8726:Parallelogram 8724: 8722: 8721:Orthodiagonal 8719: 8717: 8714: 8712: 8709: 8707: 8704: 8702: 8701:Ex-tangential 8699: 8697: 8694: 8692: 8689: 8687: 8684: 8682: 8679: 8677: 8674: 8673: 8671: 8669: 8665: 8659: 8656: 8654: 8651: 8649: 8646: 8644: 8641: 8639: 8636: 8634: 8631: 8629: 8626: 8625: 8623: 8621: 8617: 8612: 8608: 8601: 8596: 8594: 8589: 8587: 8582: 8581: 8578: 8569: 8565: 8561: 8556: 8553: 8549: 8546: 8544: 8537: 8530: 8524: 8522: 8518: 8515: 8513: 8509: 8505: 8501: 8498: 8496: 8492: 8489: 8487: 8483: 8479: 8478: 8475: 8473: 8471: 8468: 8466: 8462: 8459: 8457: 8454: 8452: 8449: 8448: 8445: 8443: 8441: 8438: 8436: 8432: 8429: 8427: 8424: 8422: 8419: 8418: 8415: 8413: 8406: 8399: 8393: 8391: 8388: 8386: 8382: 8379: 8377: 8374: 8372: 8369: 8368: 8365: 8363: 8356: 8349: 8343: 8341: 8338: 8336: 8332: 8329: 8327: 8324: 8322: 8319: 8318: 8315: 8313: 8306: 8300: 8298: 8295: 8293: 8289: 8286: 8284: 8281: 8279: 8276: 8275: 8272: 8270: 8268: 8265: 8263: 8259: 8256: 8254: 8251: 8249: 8246: 8245: 8242: 8238: 8235: 8233: 8230: 8228: 8227:Demitesseract 8225: 8223: 8219: 8216: 8214: 8211: 8209: 8206: 8205: 8202: 8198: 8195: 8193: 8191: 8188: 8186: 8182: 8179: 8177: 8174: 8172: 8169: 8168: 8165: 8162: 8160: 8157: 8155: 8152: 8150: 8147: 8145: 8142: 8140: 8137: 8136: 8133: 8127: 8124: 8120: 8113: 8109: 8102: 8098: 8093: 8089: 8084: 8080: 8075: 8073: 8071: 8067: 8057: 8053: 8051: 8049: 8045: 8041: 8039: 8037: 8033: 8029: 8027: 8024: 8023: 8018: 8014: 8006: 8001: 7999: 7994: 7992: 7987: 7986: 7983: 7974: 7973: 7968: 7965: 7960: 7959: 7946: 7942: 7938: 7934: 7930: 7926: 7919: 7911: 7905: 7901: 7900: 7892: 7884: 7878: 7874: 7869: 7868: 7859: 7851: 7845: 7841: 7840:160, 224, 226 7837: 7836: 7828: 7820: 7816: 7812: 7808: 7804: 7799: 7798: 7792: 7786: 7772: 7768: 7761: 7746: 7742: 7735: 7727: 7723: 7719: 7715: 7711: 7707: 7703: 7697: 7693: 7692: 7686: 7678: 7670: 7666: 7662: 7658: 7654: 7648: 7644: 7640: 7636: 7632: 7631: 7626: 7620: 7618: 7609: 7605: 7601: 7597: 7593: 7589: 7585: 7581: 7577: 7573: 7569: 7565: 7564: 7556: 7552: 7548: 7542: 7534: 7530: 7523: 7516: 7508: 7504: 7500: 7496: 7492: 7488: 7484: 7480: 7473: 7465: 7461: 7454: 7447: 7439: 7435: 7428: 7421: 7414: 7408: 7400: 7396: 7389: 7382: 7374: 7370: 7363: 7356: 7348: 7341: 7334: 7333: 7326: 7319: 7313: 7306:. Dover Publ. 7304: 7303: 7294: 7292: 7290: 7282: 7276: 7274: 7262: 7256: 7254: 7245: 7241: 7234: 7227: 7225: 7216: 7209: 7202: 7194: 7190: 7186: 7182: 7178: 7176:9780883857632 7172: 7168: 7164: 7160: 7155: 7154: 7148: 7141: 7133: 7129: 7125: 7121: 7117: 7111: 7107: 7103: 7099: 7094: 7093: 7084: 7082: 7080: 7071: 7067: 7063: 7056: 7049: 7047: 7038: 7034: 7030: 7026: 7022: 7018: 7014: 7010: 7006: 7000: 6996: 6992: 6988: 6984: 6983: 6975: 6973: 6964: 6960: 6956: 6952: 6948: 6944: 6940: 6936: 6932: 6928: 6924: 6923: 6915: 6907: 6903: 6899: 6895: 6891: 6887: 6883: 6879: 6872: 6865: 6857: 6853: 6849: 6845: 6841: 6837: 6833: 6829: 6825: 6821: 6814: 6807: 6803: 6793: 6790: 6788: 6785: 6783: 6780: 6778: 6775: 6774: 6765: 6761: 6757: 6754: 6750: 6746: 6743: 6739: 6738: 6737: 6729: 6715: 6712: 6709: 6701: 6685: 6676: 6674: 6670: 6669:star polygons 6654: 6651: 6643: 6639: 6635: 6631: 6627: 6623: 6619: 6615: 6611: 6602: 6598: 6596: 6592: 6588: 6584: 6580: 6576: 6572: 6568: 6559: 6555: 6542: 6539: 6534: 6530: 6524: 6520: 6516: 6511: 6507: 6503: 6500: 6495: 6491: 6470: 6448: 6444: 6421: 6417: 6394: 6390: 6381: 6380:complex plane 6376: 6363: 6358: 6355: 6350: 6343: 6339: 6333: 6329: 6323: 6318: 6315: 6288: 6284: 6261: 6257: 6248: 6247: 6231: 6223: 6218: 6214: 6204: 6203: 6182: 6177: 6173: 6163: 6162: 6161: 6158: 6156: 6153:which is the 6140: 6135: 6132: 6127: 6122: 6119: 6114: 6109: 6106: 6084: 6081: 6078: 6052: 6048: 6044: 6039: 6035: 6027: 6023: 6019: 6014: 6010: 5985: 5979: 5976: 5973: 5966: 5962: 5958: 5955: 5952: 5949: 5944: 5940: 5933: 5930: 5910: 5890: 5887: 5867: 5847: 5844: 5824: 5821: 5801: 5798: 5778: 5775: 5755: 5752: 5732: 5723: 5710: 5705: 5701: 5697: 5692: 5688: 5684: 5681: 5678: 5675: 5670: 5666: 5646: 5643: 5640: 5637: 5634: 5631: 5611: 5591: 5571: 5551: 5531: 5511: 5491: 5488: 5468: 5459: 5446: 5441: 5437: 5433: 5430: 5426: 5420: 5416: 5412: 5407: 5403: 5399: 5394: 5390: 5385: 5381: 5362: 5357: 5353: 5349: 5346: 5342: 5336: 5332: 5328: 5323: 5319: 5315: 5310: 5306: 5301: 5297: 5277: 5257: 5237: 5217: 5208: 5194: 5174: 5154: 5134: 5130: 5124: 5120: 5114: 5110: 5106: 5103: 5098: 5093: 5087: 5083: 5079: 5074: 5070: 5065: 5059: 5055: 5052: 5047: 5043: 5039: 5034: 5030: 5026: 5021: 5017: 4997: 4993: 4987: 4983: 4979: 4974: 4970: 4965: 4961: 4958: 4953: 4949: 4945: 4940: 4936: 4932: 4927: 4923: 4902: 4882: 4862: 4842: 4833: 4820: 4815: 4810: 4804: 4800: 4796: 4791: 4787: 4783: 4778: 4774: 4770: 4765: 4761: 4756: 4751: 4747: 4741: 4737: 4733: 4728: 4724: 4720: 4715: 4711: 4707: 4702: 4698: 4693: 4689: 4669: 4649: 4629: 4609: 4589: 4569: 4549: 4540: 4538: 4522: 4502: 4482: 4462: 4459: 4456: 4433: 4430: 4427: 4404: 4401: 4398: 4387: 4371: 4363: 4359: 4343: 4323: 4314: 4301: 4298: 4293: 4290: 4268: 4248: 4240: 4235: 4233: 4229: 4224: 4220: 4216: 4212: 4194: 4179: 4175: 4171: 4167: 4157: 4141: 4137: 4131: 4127: 4121: 4118: 4115: 4110: 4106: 4100: 4095: 4091: 4085: 4082: 4079: 4074: 4071: 4066: 4063: 4040: 4036: 4023: 4010: 4005: 4001: 3997: 3994: 3991: 3988: 3983: 3980: 3975: 3972: 3963: 3950: 3947: 3944: 3941: 3938: 3935: 3930: 3927: 3922: 3919: 3899: 3879: 3859: 3851: 3841: 3828: 3823: 3819: 3813: 3809: 3803: 3800: 3780: 3777: 3772: 3769: 3747: 3740:Substituting 3738: 3725: 3722: 3717: 3713: 3707: 3704: 3682: 3678: 3674: 3669: 3665: 3661: 3656: 3651: 3646: 3643: 3638: 3629: 3613: 3593: 3571: 3566: 3555: 3551: 3538: 3535: 3532: 3527: 3524: 3519: 3516: 3496: 3476: 3462: 3448: 3426: 3422: 3416: 3412: 3406: 3403: 3386: 3382: 3380: 3379: 3372: 3370: 3369:vesica piscis 3365: 3351: 3342: 3340: 3336: 3327: 3318: 3316: 3300: 3292: 3276: 3273: 3253: 3250: 3230: 3227: 3207: 3204: 3184: 3181: 3161: 3158: 3150: 3134: 3131: 3128: 3108: 3100: 3096: 3082: 3062: 3059: 3056: 3053: 3050: 3047: 3044: 3041: 3021: 3001: 2981: 2961: 2941: 2933: 2929: 2927: 2923: 2919: 2914: 2911: 2907: 2905: 2901: 2879: 2876: 2873: 2853: 2850: 2847: 2827: 2824: 2821: 2818: 2810: 2807: 2792: 2789: 2786: 2766: 2763: 2760: 2740: 2737: 2734: 2714: 2711: 2691: 2688: 2668: 2665: 2645: 2642: 2622: 2619: 2599: 2596: 2588: 2573: 2570: 2567: 2559: 2558: 2554: 2531: 2526: 2522: 2518: 2513: 2509: 2505: 2500: 2496: 2492: 2488: 2482: 2478: 2474: 2469: 2465: 2461: 2456: 2452: 2447: 2443: 2423: 2403: 2383: 2363: 2343: 2323: 2303: 2295: 2291: 2290: 2281: 2278: 2277: 2276: 2274: 2261: 2257: 2253: 2250: 2246: 2242: 2238: 2237: 2236: 2234: 2230: 2226: 2213: 2209: 2206: 2202: 2199: 2195: 2194: 2193: 2191: 2184:Equal cevians 2165: 2161: 2157: 2152: 2148: 2144: 2139: 2135: 2127: 2111: 2105: 2101: 2097: 2092: 2088: 2084: 2079: 2075: 2068: 2065: 2058: 2042: 2038: 2034: 2029: 2025: 2021: 2016: 2012: 2008: 2003: 1999: 1995: 1988: 1973: 1970: 1967: 1964: 1957: 1956: 1933: 1930: 1921: 1918: 1915: 1907: 1903: 1897: 1894: 1887: 1884: 1862: 1857: 1850: 1846: 1842: 1837: 1833: 1829: 1824: 1820: 1813: 1810: 1803: 1802: 1780: 1777: 1772: 1767: 1764: 1759: 1756: 1751: 1748: 1743: 1740: 1735: 1732: 1727: 1724: 1717: 1701: 1698: 1693: 1689: 1685: 1682: 1679: 1675: 1671: 1668: 1665: 1661: 1657: 1654: 1647: 1631: 1627: 1623: 1620: 1617: 1614: 1611: 1608: 1601: 1600: 1580: 1575: 1569: 1564: 1558: 1555: 1548: 1534: 1529: 1524: 1521: 1518: 1511: 1497: 1492: 1487: 1484: 1479: 1475: 1467: 1453: 1450: 1447: 1444: 1439: 1435: 1431: 1428: 1423: 1419: 1411: 1396: 1392: 1388: 1385: 1380: 1375: 1371: 1367: 1364: 1361: 1358: 1355: 1348: 1347: 1344:Semiperimeter 1324: 1321: 1318: 1311: 1307: 1303: 1300: 1297: 1294: 1291: 1285: 1280: 1277: 1272: 1267: 1264: 1259: 1254: 1251: 1242: 1228: 1225: 1222: 1219: 1216: 1209: 1208: 1202: 1199: 1195: 1191: 1175: 1155: 1135: 1115: 1095: 1073: 1069: 1046: 1042: 1019: 1015: 1007: 991: 984: 968: 961: 960:semiperimeter 945: 925: 905: 885: 882: 879: 865: 846: 843: 838: 835: 827: 811: 807: 804: 798: 795: 787: 771: 768: 758: 754: 737: 731: 727: 721: 718: 710: 709: 708: 689: 685: 679: 673: 668: 662: 659: 651: 650: 649: 647: 643: 624: 619: 615: 609: 606: 598: 594: 591: 575: 572: 567: 564: 544: 539: 535: 529: 526: 518: 514: 497: 493: 488: 485: 477: 473: 457: 454: 451: 448: 440: 426: 421: 417: 411: 407: 401: 398: 390: 389: 388: 386: 370: 344: 340: 336: 331: 327: 323: 318: 314: 293: 290: 287: 284: 281: 261: 258: 255: 252: 249: 240: 231: 229: 225: 221: 217: 213: 209: 205: 201: 197: 187: 184: 180: 176: 159: 155: 148: 144: 133: 131: 127: 124: 118: 116: 112: 92: 90: 86: 82: 80: 76: 72: 70: 66: 62: 59: 56: 52: 48: 43: 38: 33: 19: 8901:>20 sides 8836:Decagon (10) 8821:Heptagon (7) 8811:Pentagon (5) 8801:Triangle (3) 8696:Equidiagonal 8632: 8547: 8516: 8507: 8499: 8490: 8481: 8461:10-orthoplex 8197:Dodecahedron 8143: 8118: 8107: 8096: 8087: 8078: 8069: 8065: 8055: 8047: 8043: 8035: 8031: 7970: 7928: 7924: 7918: 7898: 7891: 7866: 7858: 7834: 7827: 7796: 7785: 7774:. Retrieved 7770: 7760: 7749:. Retrieved 7744: 7734: 7689: 7677: 7629: 7567: 7561: 7541: 7532: 7528: 7515: 7482: 7478: 7472: 7463: 7459: 7446: 7437: 7433: 7420: 7412: 7407: 7398: 7394: 7381: 7372: 7368: 7355: 7346: 7340: 7330: 7325: 7317: 7312: 7301: 7280: 7243: 7239: 7214: 7201: 7152: 7140: 7091: 7061: 6981: 6926: 6920: 6914: 6881: 6877: 6864: 6823: 6819: 6806: 6787:Ternary plot 6742:Gateway Arch 6735: 6677: 6672: 6607: 6564: 6377: 6306: 6159: 5724: 5460: 5209: 4834: 4541: 4315: 4236: 4230:that can be 4163: 4024: 3964: 3850:trigonometry 3847: 3739: 3585: 3468: 3395: 3377: 3373: 3366: 3343: 3339:Fermat prime 3332: 3289:satisfy the 3149:circumcircle 3097: 2930: 2915: 2908: 2898: 2658:parallel to 2293: 2270: 2241:circumcenter 2222: 2187: 1190:circumcircle 1088:(tangent to 871: 863: 711:The area is 706: 646:trigonometry 641: 639: 391:The area is 362: 227: 199: 193: 9097:Star-shaped 9072:Rectilinear 9042:Equilateral 9037:Equiangular 9001:Hendecagram 8845:11–20 sides 8826:Octagon (8) 8816:Hexagon (6) 8791:Monogon (1) 8633:Equilateral 8470:10-demicube 8431:9-orthoplex 8381:8-orthoplex 8331:7-orthoplex 8288:6-orthoplex 8258:5-orthoplex 8213:Pentachoron 8201:Icosahedron 8176:Tetrahedron 7466:(1): 32–35. 6933:: 247–248. 6626:icosahedron 6618:tetrahedron 3220:. That is, 2256:Nagel point 2249:orthocenter 1883:Weitzenböck 872:A triangle 212:equiangular 9122:Categories 9102:Tangential 9006:Dodecagram 8784:1–10 sides 8775:By number 8756:Tangential 8736:Right kite 8456:10-simplex 8440:9-demicube 8390:8-demicube 8340:7-demicube 8297:6-demicube 8267:5-demicube 8181:Octahedron 7819:0031.06502 7776:2023-03-09 7751:2023-03-09 7726:0888.52012 7669:1396.51001 7608:0385.51006 7535:: 105–114. 7375:: 197–209. 7098:Birkhäuser 7037:1163.00008 6963:0116.12902 6906:1162.51305 6856:1163.26316 6798:References 6764:yield sign 6760:road signs 6622:octahedron 4166:reflection 3572:of 60° is 2586:are shown. 2233:Euler line 2210:The three 2203:The three 2196:The three 9082:Reinhardt 8991:Enneagram 8981:Heptagram 8971:Pentagram 8938:65537-gon 8796:Digon (2) 8766:Trapezoid 8731:Rectangle 8681:Bicentric 8643:Isosceles 8620:Triangles 8504:orthoplex 8426:9-simplex 8376:8-simplex 8326:7-simplex 8283:6-simplex 8253:5-simplex 8222:Tesseract 7972:MathWorld 7945:109362577 7691:Polyhedra 7661:125948074 7600:123776612 7246:: 97–109. 7193:118179744 7185:501976971 7132:118951675 7124:871539199 7070:124244932 7029:117769827 7021:775429168 6955:124726536 6898:123965364 6890:1443-5756 6848:115305257 6832:1443-5756 6700:simplexes 6610:polyhedra 6521:ω 6504:ω 6471:ω 6351:≤ 6324:≤ 6174:π 6082:≠ 6045:− 6020:− 4454:∠ 4425:∠ 4396:∠ 4232:inscribed 4219:altitudes 4086:× 4006:∘ 3998:⁡ 3945:⁡ 3568:, as the 3376:Euclid's 2926:perimeter 2493:≥ 2251:coincide. 2198:altitudes 1760:⁡ 1744:⁡ 1728:⁡ 1686:⁡ 1672:⁡ 1658:⁡ 1632:∘ 1409:(Blundon) 1386:− 1301:− 294:γ 288:β 282:α 220:congruent 218:are also 9057:Isotoxal 9052:Isogonal 8996:Decagram 8986:Octagram 8976:Hexagram 8777:of sides 8706:Harmonic 8607:Polygons 8558:Topics: 8521:demicube 8486:polytope 8480:Uniform 8241:600-cell 8237:120-cell 8190:Demicube 8164:Pentagon 8144:Triangle 7793:(1948). 7718:41212721 7627:(2018). 7507:15049234 7499:27642581 7440:: 58–65. 7149:(2010). 6771:See also 6751:and the 6642:parallel 6593:are all 5768:divides 5745:on side 3697:so that 3378:Elements 2245:incenter 2229:centroid 1194:incircle 597:altitude 204:triangle 196:geometry 69:vertices 9077:Regular 9022:Concave 9015:Classes 8923:257-gon 8746:Rhombus 8686:Crossed 8495:simplex 8465:10-cube 8232:24-cell 8218:16-cell 8159:Hexagon 8013:regular 7811:4766401 7710:1458063 7592:1567647 7584:2689529 7013:2498836 6947:2687913 6840:2491926 6702:, with 6587:3.4.3.4 6579:3.4.6.4 5923:, then 4176:is the 4056:. Thus 3575:√ 3561:√ 2273:medians 2205:medians 2190:cevians 1006:exradii 757:apothem 183:degrees 9087:Simple 9032:Cyclic 9027:Convex 8751:Square 8691:Cyclic 8653:Obtuse 8648:Kepler 8435:9-cube 8385:8-cube 8335:7-cube 8292:6-cube 8262:5-cube 8149:Square 8026:Family 7943:  7906:  7879:  7846:  7817:  7809:  7771:Stella 7724:  7716:  7708:  7698:  7667:  7659:  7649:  7606:  7598:  7590:  7582:  7505:  7497:  7401:: 7–8. 7191:  7183:  7173:  7130:  7122:  7112:  7068:  7035:  7027:  7019:  7011:  7001:  6961:  6953:  6945:  6904:  6896:  6888:  6854:  6846:  6838:  6830:  6589:, and 6436:, and 6303:, then 5604:, and 5544:, and 5270:, and 5147:where 4895:, and 4662:, and 4602:, and 4515:, and 4446:, and 4228:square 3848:Using 3266:, and 3197:, and 2994:, and 2635:, and 2589:Lines 2416:, and 2356:, and 2296:point 2223:Every 1597:Angles 648:that: 387:that: 216:angles 9062:Magic 8658:Right 8638:Ideal 8628:Acute 8154:p-gon 7941:S2CID 7657:S2CID 7596:S2CID 7580:JSTOR 7558:(PDF) 7525:(PDF) 7503:S2CID 7495:JSTOR 7456:(PDF) 7430:(PDF) 7391:(PDF) 7365:(PDF) 7264:(PDF) 7236:(PDF) 7211:(PDF) 7189:S2CID 7128:S2CID 7066:S2CID 7058:(PDF) 7025:S2CID 6951:S2CID 6943:JSTOR 6929:(4). 6894:S2CID 6874:(PDF) 6844:S2CID 6816:(PDF) 6583:(3.6) 6567:tiles 5837:with 5564:from 2294:every 1205:Sides 759:, is 202:is a 198:, an 65:Edges 9092:Skew 8716:Kite 8611:List 8512:cube 8185:Cube 8015:and 7904:ISBN 7877:ISBN 7844:ISBN 7807:OCLC 7714:OCLC 7696:ISBN 7647:ISBN 7181:OCLC 7171:ISBN 7120:OCLC 7110:ISBN 7017:OCLC 6999:ISBN 6886:ISSN 6828:ISSN 6624:and 6575:3.12 6276:and 6097:and 5880:and 5814:and 4168:and 3872:and 3570:sine 2922:area 2779:and 2704:and 1799:Area 1192:and 1168:and 983:area 595:The 130:Area 67:and 54:Type 8061:(p) 7933:doi 7815:Zbl 7722:Zbl 7665:Zbl 7639:doi 7604:Zbl 7572:doi 7487:doi 7483:115 7163:doi 7102:doi 7033:Zbl 6991:doi 6959:Zbl 6935:doi 6902:Zbl 6852:Zbl 6591:3.6 6071:if 4388:of 4237:By 3995:sin 3942:sin 2811:As 1757:sin 1741:sin 1725:sin 1683:cos 1669:cos 1655:cos 557:or 519:is 478:is 194:In 188:60° 83:{3} 9124:: 8566:• 8562:• 8542:21 8538:• 8535:k1 8531:• 8528:k2 8506:• 8463:• 8433:• 8411:21 8407:• 8404:41 8400:• 8397:42 8383:• 8361:21 8357:• 8354:31 8350:• 8347:32 8333:• 8311:21 8307:• 8304:22 8290:• 8260:• 8239:• 8220:• 8199:• 8183:• 8115:/ 8104:/ 8094:/ 8085:/ 8063:/ 7969:. 7939:. 7929:24 7927:. 7875:. 7842:. 7813:. 7769:. 7743:. 7720:. 7712:. 7706:MR 7704:. 7688:. 7663:. 7655:. 7645:. 7616:^ 7602:. 7594:. 7588:MR 7586:. 7578:. 7568:50 7566:. 7560:. 7549:; 7533:15 7531:. 7527:. 7501:. 7493:. 7481:. 7464:41 7462:. 7458:. 7438:10 7436:. 7432:. 7397:. 7393:. 7373:12 7371:. 7367:. 7288:^ 7272:^ 7252:^ 7242:. 7238:. 7223:^ 7213:. 7187:. 7179:. 7169:. 7126:. 7118:. 7108:. 7078:^ 7060:. 7045:^ 7031:. 7023:. 7015:. 7009:MR 7007:. 6997:. 6971:^ 6957:. 6949:. 6941:. 6927:36 6925:. 6900:. 6892:. 6880:. 6876:. 6850:. 6842:. 6836:MR 6834:. 6824:10 6822:. 6818:. 6728:. 6620:, 6585:, 6581:, 6577:, 6573:. 6543:0. 6409:, 6219:12 6157:. 5584:, 5524:, 5434:11 5382:16 5250:, 4875:, 4642:, 4582:, 4495:, 4417:, 4302:2. 4180:, 4002:60 3580:/2 3381:. 3371:. 3317:. 3243:, 3174:, 3095:. 3034:, 2974:, 2753:, 2681:, 2612:, 2396:, 2336:, 2243:, 1628:60 1448:12 1292:25 1128:, 1108:, 1061:, 1034:, 1004:, 981:, 958:, 938:, 918:, 359:). 230:. 8613:) 8609:( 8599:e 8592:t 8585:v 8550:- 8548:n 8540:k 8533:2 8526:1 8519:- 8517:n 8510:- 8508:n 8502:- 8500:n 8493:- 8491:n 8484:- 8482:n 8409:4 8402:2 8395:1 8359:3 8352:2 8345:1 8309:2 8302:1 8131:n 8129:H 8122:2 8119:G 8111:4 8108:F 8100:8 8097:E 8091:7 8088:E 8082:6 8079:E 8070:n 8066:D 8059:2 8056:I 8048:n 8044:B 8036:n 8032:A 8004:e 7997:t 7990:v 7975:. 7947:. 7935:: 7912:. 7885:. 7873:3 7852:. 7821:. 7779:. 7754:. 7728:. 7671:. 7641:: 7610:. 7574:: 7509:. 7489:: 7399:1 7266:. 7244:4 7195:. 7165:: 7134:. 7104:: 7072:. 7039:. 6993:: 6965:. 6937:: 6908:. 6882:9 6858:. 6766:. 6755:. 6744:. 6716:2 6713:= 6710:n 6698:- 6686:n 6655:n 6652:2 6540:= 6535:3 6531:z 6525:2 6517:+ 6512:2 6508:z 6501:+ 6496:1 6492:z 6449:3 6445:z 6422:2 6418:z 6395:1 6391:z 6364:. 6359:7 6356:9 6344:2 6340:A 6334:1 6330:A 6319:9 6316:7 6289:2 6285:A 6262:1 6258:A 6232:, 6224:3 6215:1 6183:3 6178:3 6141:, 6136:y 6133:1 6128:= 6123:t 6120:1 6115:+ 6110:q 6107:1 6085:q 6079:t 6053:2 6049:q 6040:2 6036:t 6028:3 6024:q 6015:3 6011:t 5986:, 5980:q 5977:+ 5974:t 5967:2 5963:q 5959:+ 5956:q 5953:t 5950:+ 5945:2 5941:t 5934:= 5931:z 5911:y 5891:D 5888:P 5868:z 5848:A 5845:D 5825:A 5822:D 5802:D 5799:P 5779:A 5776:P 5756:C 5753:B 5733:D 5711:. 5706:2 5702:a 5698:= 5693:2 5689:t 5685:+ 5682:t 5679:q 5676:+ 5671:2 5667:q 5647:, 5644:t 5641:+ 5638:q 5635:= 5632:p 5612:C 5592:B 5572:A 5552:t 5532:q 5512:p 5492:C 5489:B 5469:P 5447:. 5442:4 5438:a 5431:= 5427:) 5421:4 5417:t 5413:+ 5408:4 5404:q 5400:+ 5395:4 5391:p 5386:( 5363:, 5358:2 5354:a 5350:5 5347:= 5343:) 5337:2 5333:t 5329:+ 5324:2 5320:q 5316:+ 5311:2 5307:p 5302:( 5298:4 5278:t 5258:q 5238:p 5218:P 5195:P 5175:L 5155:R 5135:, 5131:] 5125:2 5121:L 5115:2 5111:R 5107:2 5104:+ 5099:2 5094:) 5088:2 5084:L 5080:+ 5075:2 5071:R 5066:( 5060:[ 5056:3 5053:= 5048:4 5044:t 5040:+ 5035:4 5031:q 5027:+ 5022:4 5018:p 4998:, 4994:) 4988:2 4984:L 4980:+ 4975:2 4971:R 4966:( 4962:3 4959:= 4954:2 4950:t 4946:+ 4941:2 4937:q 4933:+ 4928:2 4924:p 4903:t 4883:q 4863:p 4843:P 4821:. 4816:2 4811:) 4805:2 4801:a 4797:+ 4792:2 4788:t 4784:+ 4779:2 4775:q 4771:+ 4766:2 4762:p 4757:( 4752:= 4748:) 4742:4 4738:a 4734:+ 4729:4 4725:t 4721:+ 4716:4 4712:q 4708:+ 4703:4 4699:p 4694:( 4690:3 4670:C 4650:B 4630:A 4610:t 4590:q 4570:p 4550:P 4523:C 4503:B 4483:A 4463:A 4460:P 4457:C 4434:C 4431:P 4428:B 4405:B 4402:P 4399:A 4372:P 4344:P 4324:P 4299:= 4294:r 4291:R 4269:r 4249:R 4195:3 4190:D 4142:2 4138:a 4132:4 4128:3 4122:= 4119:b 4116:a 4111:4 4107:3 4101:= 4096:2 4092:3 4083:b 4080:a 4075:2 4072:1 4067:= 4064:A 4041:2 4037:3 4011:. 3992:b 3989:a 3984:2 3981:1 3976:= 3973:A 3951:. 3948:C 3939:b 3936:a 3931:2 3928:1 3923:= 3920:A 3900:C 3880:b 3860:a 3829:. 3824:2 3820:a 3814:4 3810:3 3804:= 3801:A 3781:h 3778:a 3773:2 3770:1 3748:h 3726:. 3723:a 3718:2 3714:3 3708:= 3705:h 3683:2 3679:a 3675:= 3670:2 3666:h 3662:+ 3657:2 3652:) 3647:2 3644:a 3639:( 3614:a 3594:a 3582:. 3577:3 3563:3 3539:. 3536:h 3533:a 3528:2 3525:1 3520:= 3517:A 3497:h 3477:a 3449:a 3427:2 3423:a 3417:4 3413:3 3407:= 3404:A 3352:r 3301:P 3277:C 3274:P 3254:B 3251:P 3231:A 3228:P 3208:C 3205:P 3185:B 3182:P 3162:A 3159:P 3135:C 3132:B 3129:A 3109:P 3083:P 3063:, 3060:h 3057:= 3054:f 3051:+ 3048:e 3045:+ 3042:d 3022:h 3002:f 2982:e 2962:d 2942:P 2892:. 2880:C 2877:B 2874:A 2854:E 2851:H 2848:P 2828:H 2825:C 2822:G 2819:P 2805:. 2793:G 2790:D 2787:P 2767:I 2764:F 2761:P 2741:E 2738:H 2735:P 2715:A 2712:C 2692:C 2689:B 2669:B 2666:A 2646:I 2643:H 2623:G 2620:F 2600:E 2597:D 2574:C 2571:B 2568:A 2532:. 2527:2 2523:z 2519:+ 2514:2 2510:y 2506:+ 2501:2 2497:x 2489:) 2483:2 2479:r 2475:+ 2470:2 2466:q 2462:+ 2457:2 2453:p 2448:( 2444:4 2424:z 2404:y 2384:x 2364:r 2344:q 2324:p 2304:P 2262:. 2166:c 2162:r 2158:= 2153:b 2149:r 2145:= 2140:a 2136:r 2112:9 2106:c 2102:r 2098:+ 2093:b 2089:r 2085:+ 2080:a 2076:r 2069:= 2066:r 2043:2 2039:c 2035:+ 2030:2 2026:b 2022:+ 2017:2 2013:a 2009:= 2004:2 2000:R 1996:9 1974:r 1971:2 1968:= 1965:R 1934:3 1931:2 1926:) 1922:c 1919:b 1916:a 1913:( 1908:4 1904:3 1898:= 1895:T 1885:) 1881:( 1863:3 1858:4 1851:2 1847:c 1843:+ 1838:2 1834:b 1830:+ 1825:2 1821:a 1814:= 1811:T 1781:8 1778:1 1773:= 1768:2 1765:C 1752:2 1749:B 1736:2 1733:A 1702:2 1699:3 1694:= 1690:C 1680:+ 1676:B 1666:+ 1662:A 1624:= 1621:C 1618:= 1615:B 1612:= 1609:A 1581:R 1576:2 1570:3 1565:3 1559:= 1556:s 1535:r 1530:3 1525:3 1522:= 1519:s 1498:T 1493:3 1488:3 1485:= 1480:2 1476:s 1454:r 1451:R 1445:+ 1440:2 1436:r 1432:3 1429:= 1424:2 1420:s 1397:r 1393:) 1389:4 1381:3 1376:3 1372:( 1368:+ 1365:R 1362:2 1359:= 1356:s 1325:r 1322:R 1319:4 1312:2 1308:r 1304:2 1298:r 1295:R 1286:= 1281:c 1278:1 1273:+ 1268:b 1265:1 1260:+ 1255:a 1252:1 1229:c 1226:= 1223:b 1220:= 1217:a 1176:r 1156:R 1136:c 1116:b 1096:a 1074:c 1070:r 1047:b 1043:r 1020:a 1016:r 992:T 969:s 946:c 926:b 906:a 886:C 883:B 880:A 847:3 844:h 839:= 836:r 812:3 808:h 805:2 799:= 796:R 772:3 769:h 738:3 732:2 728:h 722:= 719:A 690:2 686:R 680:4 674:3 669:3 663:= 660:A 642:R 625:a 620:2 616:3 610:= 607:h 576:2 573:R 568:= 565:r 545:a 540:6 536:3 530:= 527:r 498:3 494:a 489:= 486:R 458:a 455:3 452:= 449:p 427:, 422:2 418:a 412:4 408:3 402:= 399:A 371:a 345:c 341:h 337:= 332:b 328:h 324:= 319:a 315:h 291:= 285:= 262:c 259:= 256:b 253:= 250:a 185:) 181:( 160:2 156:a 149:4 145:3 122:3 120:D 73:3 34:. 20:)

Index

Regular triangle
Equilateral (disambiguation)

Regular polygon
Edges
vertices
Schläfli symbol
Coxeter–Dynkin diagrams
Symmetry group
D3
Area
Internal angle
degrees
geometry
triangle
Euclidean geometry
equiangular
angles
congruent
regular polygon

Pythagorean theorem
circumscribed circle
inscribed circle
altitude
trigonometry
apothem
semiperimeter
area
exradii

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