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Line (geometry)

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70: 5724: 2293: 4640: 5435: 5371: 2035: 4095: 5689: 44: 1879: 1337:) was defined as a line "which lies evenly with the points on itself". These definitions appeal to readers' physical experience, relying on terms that are not themselves defined, and the definitions are never explicitly referenced in the remainder of the text. In modern geometry, a line is usually either taken as a 2042:
In a sense, all lines in Euclidean geometry are equal, in that, without coordinates, one can not tell them apart from one another. However, lines may play special roles with respect to other objects in the geometry and be divided into types according to that relationship. For instance, with respect
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of a primitive notion, to give a foundation to build the notion on which would formally be based on the (unstated) axioms. Descriptions of this type may be referred to, by some authors, as definitions in this informal style of presentation. These are not true definitions, and could not be used in
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is a part of a line that is bounded by two distinct end points and contains every point on the line between its end points. Depending on how the line segment is defined, either of the two end points may or may not be part of the line segment. Two or more line segments may have some of the same
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Equivalently for three points in a plane, the points are collinear if and only if the slope between one pair of points equals the slope between any other pair of points (in which case the slope between the remaining pair of points will equal the other slopes). By extension,
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passing through the origin. Even though these representations are visually distinct, they satisfy all the properties (such as, two points determining a unique line) that make them suitable representations for lines in this geometry.
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In a non-axiomatic or simplified axiomatic treatment of geometry, the concept of a primitive notion may be too abstract to be dealt with. In this circumstance, it is possible to provide a
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perpendicular to the line. This segment joins the origin with the closest point on the line to the origin. The normal form of the equation of a straight line on the plane is given by:
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object). The properties of lines are then determined by the axioms which refer to them. One advantage to this approach is the flexibility it gives to users of the geometry. Thus in
3886: 1874:{\displaystyle {\begin{bmatrix}1&x_{1}&x_{2}&\cdots &x_{n}\\1&y_{1}&y_{2}&\cdots &y_{n}\\1&z_{1}&z_{2}&\cdots &z_{n}\end{bmatrix}}} 3725: 3666: 3440: 2638: 2582: 5126: 5088: 3293: 3253: 3204: 2463:
There are many variant ways to write the equation of a line which can all be converted from one to another by algebraic manipulation. The above form is sometimes called the
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The definition of a ray depends upon the notion of betweenness for points on a line. It follows that rays exist only for geometries for which this notion exists, typically
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These forms are generally named by the type of information (data) about the line that is needed to write down the form. Some of the important data of a line is its slope,
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defines a plane, so two such equations, provided the planes they give rise to are not parallel, define a line which is the intersection of the planes. More generally, in
2512: 1368:(modern mathematicians added to Euclid's original axioms to fill perceived logical gaps), a line is stated to have certain properties that relate it to other lines and 4889: 4479: 4376: 4343: 4202: 5200: 4252: 3101: 3852: 2267:), there is no generally accepted agreement among authors as to what an informal description of a line should be when the subject is not being treated formally. 2322: 4080:
Parametric equations for lines in higher dimensions are similar in that they are based on the specification of one point on the line and a direction vector.
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In modern mathematics, given the multitude of geometries, the concept of a line is closely tied to the way the geometry is described. For instance, in
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share a single point in common. Coincidental lines coincide with each other—every point that is on either one of them is also on the other.
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Distance from the origin O to the line E calculated with the Hesse normal form. Normal vector in red, line in green, point O shown in blue.
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of a sphere with diametrically opposite points identified. In a different model of elliptic geometry, lines are represented by Euclidean
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are evenly spaced on the line, with positive numbers are on the right, negative numbers on the left. As an extension to the concept, an
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The previous forms do not apply for a line passing through the origin, but a simpler formula can be written: the polar coordinates
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defines a straight line as a "breadthless length" that "lies evenly with respect to the points on itself", and introduced several
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relationships as lines, such as being parallel, intersecting, or skew, but unlike lines they may be none of these, if they are
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Unlike the slope-intercept and intercept forms, this form can represent any line but also requires only two finite parameters,
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of the equation. However, this terminology is not universally accepted, and many authors do not distinguish these two forms.
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that has a point of the line and the origin as vertices, and the line and its perpendicular through the origin as sides.
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are terms introduced to avoid confusion with generalizations introduced since the end of the 19th century, such as
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we see a typical example of this. In the spherical representation of elliptic geometry, lines are represented by
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A line on polar coordinates without passing though the origin, with the general parametric equation written above
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A great circle divides the sphere in two equal hemispheres, while also satisfying the "no curvature" property.
6385: 6295: 6282: 5976: 4901: 17: 5301:{\displaystyle r\geq 0,\qquad {\text{and}}\quad \theta =\alpha \quad {\text{or}}\quad \theta =\alpha +\pi .} 3071: 6411: 5740: 2083: 6380: 6277: 5129: 3671: 3612: 2189: 1447: 1358: 52: 3384: 2587: 2531: 6416: 6200: 6104: 3049:{\displaystyle y=x\,{\frac {y_{1}-y_{0}}{x_{1}-x_{0}}}+{\frac {x_{1}y_{0}-x_{0}y_{1}}{x_{1}-x_{0}}}\,.} 2263:
falls into this category. Even in the case where a specific geometry is being considered (for example,
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is the (positive) length of the normal segment. The normal form can be derived from the standard form
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The Student's Introduction to MATHEMATICA: A Handbook for Precalculus, Calculus, and Linear Algebra
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is the angle of inclination of the normal segment (the oriented angle from the unit vector of the
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is described by limiting λ. One ray is obtained if λ ≥ 0, and the opposite ray comes from λ ≤ 0.
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As a note, lines in three dimensions may also be described as the simultaneous solutions of two
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A number line, with variable x on the left and y on the right. Therefore, x is smaller than y.
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Tangent to a curve. The red line is tangential to the curve at the point marked by a red dot.
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if they lie on the same line. If three points are not collinear, there is exactly one
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is a line that intersects two other lines that may or not be parallel to each other.
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The "shortness" and "straightness" of a line, interpreted as the property that the
5391: 5341: 3855: 2276: 2236: 2232: 2086:, whose distance from a point helps to establish whether the point is on the conic. 2079:
exterior lines, which do not meet the conic at any point of the Euclidean plane; or
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Nunemacher, Jeffrey (1999), "Asymptotes, Cubic Curves, and the Projective Plane",
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On occasion we may consider a ray without its initial point. Such rays are called
5493:. As two points define a unique line, this ray consists of all the points between 6354: 5784: 5655: 5326: 5316: 4648: 3446: 2287: 2109: 2090: 1889:= 2), the above matrix is square and the points are collinear if and only if its 1454: 1396: 1297: 533: 239: 222: 163: 69: 33: 6177:
Plane Analytic Geometry: With Introductory Chapters on the Differential Calculus
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are not both zero. Using this form, vertical lines correspond to equations with
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can be drawn perpendicular to the number line at zero. The two lines forms the
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are lines that are not in the same plane and thus do not intersect each other.
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Parametric equations are also used to specify lines, particularly in those in
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as basic unprovable properties on which the rest of geometry was established.
1135: 746: 6405: 5937: 5748: 5659: 4639: 4617:{\displaystyle \mathbf {r} =\mathbf {a} +\lambda (\mathbf {b} -\mathbf {a} )} 2166: 2044: 1140: 1125: 1054: 871: 831: 781: 556: 519: 486: 324: 320: 3883:
In three dimensions lines are frequently described by parametric equations:
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of the points of a line passing through the origin and making an angle of
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for a given line, which is defined to be the line segment drawn from the
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and, in the special case where the conic is a pair of lines, we have the
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perpendicular to the line and delimited by the origin and the line, and
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In polar coordinates, the equation of a line not passing through the
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as decomposing this line into two parts. Each such part is called a
5427:"Ray (geometry)" redirects here. For other uses in mathematics, see 2304:, are characterized by linear equations. More precisely, every line 5814: 5702: 5407: 5399: 5365: 5349: 5136: 4498:
The vector equation of the line through points A and B is given by
2174: 2129:, which a curve approaches arbitrarily closely without touching it. 2056: 1548:{\displaystyle L=\left\{(1-t)\,a+tb\mid t\in \mathbb {R} \right\}.} 1364:
In an axiomatic formulation of Euclidean geometry, such as that of
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and a line is what is common to two distinct intersecting planes.
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may be used to express the collinearity between three points by:
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A ray with a terminus at A, with two points B and C on the right
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Un nouveau système de définitions pour la géométrie euclidienne
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rays, in contrast to the typical ray which would be said to be
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along the line between any two of its points is minimized (see
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It may be useful to express the equation in terms of the angle
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In Euclidean geometry two rays with a common endpoint form an
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are related to the slope of the line, such that the direction
2758:{\displaystyle (y-y_{0})(x_{1}-x_{0})=(y_{1}-y_{0})(x-x_{0}).} 2528:
The equation of the line passing through two different points
5769: 5644: 5533:. This is, at times, also expressed as the set of all points 5337: 3115: 3111: 2244: 1342: 1325: 1003: 927: 861: 706: 310: 305: 6151:(2nd ed.), New York: John Wiley & Sons, p. 4, 3060:, the equation for non-vertical lines is often given in the 1885:
less than 3. In particular, for three points in the plane (
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of points obeying a linear relationship, for instance when
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However, there are other notions of distance (such as the
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formal proofs of statements. The "definition" of line in
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The concept of line is often considered in geometry as a
43: 5310: 4385:. On the other hand, if the line is through the origin ( 2026:, other methods of determining collinearity are needed. 1575:= 1), or in other words, in the direction of the vector 1223:, is an infinitely long object with no width, depth, or 4942:-axis and the line. In this case, the equation becomes 2296:
Line graphs of linear equations on the Cartesian plane
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in spaces of dimension two, three, or higher. The word
4789:{\displaystyle r={\frac {p}{\cos(\theta -\varphi )}},} 4723:{\displaystyle x=r\cos \theta ,\quad y=r\sin \theta .} 4316:{\displaystyle {\frac {c}{|c|}}{\sqrt {a^{2}+b^{2}}}.} 3821:{\displaystyle a_{1}=ta_{2},b_{1}=tb_{2},c_{1}=tc_{2}} 1720: 1353:
are taken to be primitive and geometry is established
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nor in a geometry over a non-ordered field, like the
5244: 5212: 5188: 5156: 5096: 5058: 5011: 4991:{\displaystyle r={\frac {p}{\sin(\theta -\alpha )}},} 4948: 4904: 4877: 4809: 4746: 4676: 4575: 4504: 4467: 4441: 4415: 4364: 4331: 4260: 4222: 4190: 4131: 3889: 3834: 3733: 3674: 3615: 3534: 3454: 3387: 3301: 3261: 3212: 3163: 3074: 2900: 2787: 2646: 2590: 2534: 2473: 2342: 2310: 1714: 1483: 6195:
Torrence, Bruce F.; Torrence, Eve A. (29 Jan 2009),
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points in a plane are collinear if and only if any (
1403:(possibly unbounded); this partition is known as an 6294: 6066:
Charming Proofs: A Journey Into Elegant Mathematics
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Foundations of Euclidean and Non-Euclidean Geometry
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Ray (disambiguation) § Science and mathematics
2173:is the line that connects the midpoints of the two 2018:In the geometries where the concept of a line is a 1905:–1) pairs of points have the same pairwise slopes. 1450:variables define a line under suitable conditions. 6144: 5406:), can be generalized and leads to the concept of 5300: 5230: 5194: 5174: 5120: 5082: 5038: 4990: 4930: 4883: 4855: 4788: 4722: 4616: 4538: 4473: 4453: 4427: 4370: 4337: 4315: 4246: 4196: 4177:{\displaystyle x\cos \varphi +y\sin \varphi -p=0,} 4176: 3995: 3876:or more because in more than two dimensions lines 3846: 3820: 3719: 3660: 3601: 3521: 3434: 3373: 3287: 3247: 3198: 3095: 3048: 2886: 2757: 2632: 2576: 2506: 2399: 2316: 2300:Lines in a Cartesian plane or, more generally, in 1873: 1547: 5489:, they determine a unique ray with initial point 6403: 6194: 5922:, New York: Continuum International Pub. Group, 5577:, will determine another ray with initial point 4569:, then the equation of the line can be written: 1227:, an idealization of such physical objects as a 6227:, New York: McGraw-Hill, p. 59, definition 3, 5990: 5692:Drawing of a line segment "AB" on the line "a" 5596:Thus, we would say that two different points, 5352:(shortest path between points), while in some 4018:are all functions of the independent variable 2198:are lines in the same plane that never cross. 1380:), two lines that do not intersect are called 1329:) is defined as a "breadthless length", and a 6000:, Jones & Bartlett Learning, p. 62, 5751:, a geometrical representation of the set of 5039:{\displaystyle 0<\theta <\alpha +\pi .} 3381:and the equation of this line can be written 3374:{\displaystyle m=(y_{b}-y_{a})/(x_{b}-x_{a})} 1255:, which is a part of a line delimited by two 1192: 6063: 3602:{\displaystyle a_{2}x+b_{2}y+c_{2}z-d_{2}=0} 3522:{\displaystyle a_{1}x+b_{1}y+c_{1}z-d_{1}=0} 2525:, known points on the line and y-intercept. 2391: 2349: 2184:with vertices lying on a conic we have the 6019: 5662:. On the other hand, rays do not exist in 5329:, but in a more abstract setting, such as 3880:be described by a single linear equation. 2070:, which touch the conic at a single point; 1199: 1185: 68: 6325: 6298:; Redlin, Lothar; Watson, Saleem (2008), 6222: 6064:Alsina, Claudi; Nelsen, Roger B. (2010), 6033: 5919:Resources for teaching mathematics, 14–16 5474:and proceeding indefinitely, starting at 5336:When a geometry is described by a set of 4527: 3042: 2910: 2816: 1533: 1510: 27:Straight figure with zero width and depth 5959:International Congress of Mathematicians 5731:A point on number line corresponds to a 5722: 5687: 5433: 5369: 5048:These equations can be derived from the 4638: 4488: 4093: 2400:{\displaystyle L=\{(x,y)\mid ax+by=c\},} 2291: 2033: 42: 6270: 6142: 4931:{\displaystyle \alpha =\varphi +\pi /2} 4254:by dividing all of the coefficients by 2226: 2123:points counted without multiplicity, or 2015:) for which this property is not true. 1410: 1251:may also refer, in everyday life, to a 14: 6404: 6170: 5915: 5569:but not in the ray with initial point 5359: 5311:Generalizations of the Euclidean line 3861: 2336:) satisfy a linear equation; that is, 1559:of the line is from a reference point 299:Straightedge and compass constructions 6246: 6057: 5949: 5891: 3157:The slope of the line through points 2169:with at most two parallel sides, the 1469:passing through two different points 5887: 5885: 5883: 5881: 5879: 5877: 5875: 4634: 4083: 3727:are not proportional (the relations 2781:, this equation may be rewritten as 2119:-secant lines, meeting the curve in 1605:Three or more points are said to be 6098: 5970: 5775:Distance between two parallel lines 5705:and either do not intersect or are 5135:These equations can also be proven 4022:which ranges over the real numbers. 3720:{\displaystyle (a_{2},b_{2},c_{2})} 3661:{\displaystyle (a_{1},b_{1},c_{1})} 1594: 24: 5984: 3435:{\displaystyle y=m(x-x_{a})+y_{a}} 2633:{\displaystyle P_{1}(x_{1},y_{1})} 2577:{\displaystyle P_{0}(x_{0},y_{0})} 2281: 25: 6438: 6368: 6331:The American Mathematical Monthly 6251:, Mineola, NY: Dover, p. 2, 5872: 5348:, a line may be interpreted as a 4891:is the (oriented) angle from the 4110:, after the German mathematician 2514:and this is sometimes called the 1443:−1 first-degree equations in the 265:Noncommutative algebraic geometry 6249:Geometry: A Comprehensive Course 5121:{\displaystyle y=r\sin \theta ,} 5083:{\displaystyle x=r\cos \theta ,} 5052:of the line equation by setting 5049: 4867:is the (positive) length of the 4607: 4599: 4585: 4577: 4532: 4529: 4517: 4514: 4506: 1461:(and analogously in every other 6329:(1941), "The inversive plane", 6319: 6288: 6264: 6240: 6216: 6188: 6184:from the original on 2016-05-13 6164: 6136: 5997:Calculus with Analytic Geometry 5844: 5780:Distance from a point to a line 5677: 5279: 5273: 5263: 5257: 4698: 3288:{\displaystyle x_{a}\neq x_{b}} 2442:One can further suppose either 2093:, a linear coordinate dimension 32:For the graphical concept, see 6393:Equations of the Straight Line 6092: 6013: 5964: 5943: 5909: 5827: 5712: 5225: 5213: 5169: 5157: 4979: 4967: 4777: 4765: 4611: 4595: 4276: 4268: 3714: 3675: 3655: 3616: 3416: 3397: 3368: 3342: 3334: 3308: 3248:{\displaystyle B(x_{b},y_{b})} 3242: 3216: 3199:{\displaystyle A(x_{a},y_{a})} 3193: 3167: 2813: 2794: 2749: 2730: 2727: 2701: 2695: 2669: 2666: 2647: 2627: 2601: 2571: 2545: 2364: 2352: 2097:In the context of determining 1624:-dimensional space the points 1507: 1495: 658:- / other-dimensional 13: 1: 5994:; Protter, Philip E. (1988), 5977:The Principles of Mathematics 5865: 5417: 4454:{\displaystyle \cos \varphi } 4428:{\displaystyle \sin \varphi } 2270: 2022:, as may be the case in some 1951:are collinear if and only if 1303: 5561:, on the line determined by 4736:—the point with coordinates 4670:by the parametric equations: 4210:-axis to this segment), and 2456:, by dividing everything by 2208:are lines that intersect at 7: 6381:Encyclopedia of Mathematics 6278:Encyclopedia of Mathematics 5896:, New York: Marcel Dekker, 5758: 5442:Given a line and any point 5231:{\displaystyle (r,\theta )} 5175:{\displaystyle (r,\theta )} 4378:is uniquely defined modulo 4046:) is any point on the line. 53:Cartesian coordinate system 10: 6443: 6201:Cambridge University Press 6105:Holt, Rinehart and Winston 5892:Faber, Richard L. (1983), 5716: 5681: 5537:on the line determined by 5426: 5363: 5314: 5143:of sine and cosine to the 5141:right triangle definitions 4493: 4087: 4076:) is parallel to the line. 3865: 2507:{\displaystyle ax+by-c=0,} 2285: 2274: 1598: 31: 6068:, MAA, pp. 108–109, 5735:and vice versa. Usually, 5130:angle difference identity 2247:which they must satisfy. 2101:in Euclidean geometry, a 1591:can yield the same line. 1341:with properties given by 6271:Sidorov, L. A. (2001) , 6223:Wylie Jr., C.R. (1964), 6147:Introduction to Geometry 5820: 4884:{\displaystyle \varphi } 4627:A ray starting at point 4474:{\displaystyle \varphi } 4371:{\displaystyle \varphi } 4338:{\displaystyle \varphi } 4197:{\displaystyle \varphi } 2029: 406: 154:Non-Archimedean geometry 6225:Foundations of Geometry 6180:, H. Holt, p. 44, 6143:Coxeter, H.S.M (1969), 5446:on it, we may consider 5195:{\displaystyle \alpha } 4895:-axis to this segment. 4481:is only defined modulo 4247:{\displaystyle ax+by=c} 2217:three-dimensional space 2112:, lines could also be: 1705:) are collinear if the 1583:. Different choices of 1417:three-dimensional space 1345:, or else defined as a 260:Noncommutative geometry 51:on the two-dimensional 6099:Kay, David C. (1969), 5916:Foster, Colin (2010), 5728: 5693: 5581:. With respect to the 5481:Given distinct points 5462:. It is also known as 5439: 5422: 5375: 5302: 5232: 5196: 5176: 5128:and then applying the 5122: 5084: 5040: 4992: 4932: 4885: 4857: 4790: 4724: 4644: 4618: 4540: 4475: 4461:, and it follows that 4455: 4429: 4372: 4351:, to be specified. If 4339: 4317: 4248: 4198: 4178: 4099: 3997: 3848: 3822: 3721: 3662: 3603: 3523: 3436: 3375: 3289: 3249: 3200: 3097: 3096:{\displaystyle y=mx+b} 3050: 2888: 2759: 2634: 2578: 2508: 2401: 2318: 2297: 2039: 1875: 1567:= 0) to another point 1549: 1357:in terms of numerical 1312:deductive geometry of 1231:, a taut string, or a 1219:, usually abbreviated 228:Discrete/Combinatorial 55: 36:. For other uses, see 5765:Affine transformation 5726: 5691: 5509:) and all the points 5437: 5373: 5364:Further information: 5354:projective geometries 5346:differential geometry 5303: 5233: 5206:-axis, are the pairs 5197: 5177: 5123: 5085: 5041: 4993: 4933: 4886: 4858: 4791: 4725: 4668:Cartesian coordinates 4642: 4619: 4541: 4489:Other representations 4476: 4456: 4430: 4373: 4340: 4318: 4249: 4199: 4179: 4097: 3998: 3866:Further information: 3849: 3823: 3722: 3663: 3604: 3524: 3437: 3376: 3290: 3250: 3201: 3098: 3051: 2889: 2760: 2635: 2579: 2509: 2402: 2319: 2295: 2037: 1927:) between two points 1876: 1550: 1421:first degree equation 1376:(i.e., the Euclidean 211:Discrete differential 46: 6022:Mathematics Magazine 5841:on the set of lines. 5790:Incidence (geometry) 5513:on the line through 5466:, a one-dimensional 5242: 5210: 5186: 5154: 5132:for sine or cosine. 5094: 5056: 5009: 4946: 4902: 4875: 4807: 4744: 4674: 4573: 4502: 4465: 4439: 4413: 4362: 4329: 4258: 4220: 4188: 4129: 3887: 3832: 3731: 3672: 3613: 3532: 3452: 3385: 3299: 3259: 3210: 3161: 3136:independent variable 3072: 3063:slope–intercept form 2898: 2785: 2644: 2588: 2532: 2471: 2340: 2308: 2227:In axiomatic systems 2024:synthetic geometries 1712: 1613:that contains them. 1481: 1411:In higher dimensions 1405:arrangement of lines 47:A red line near the 6412:Elementary geometry 6247:Pedoe, Dan (1988), 5664:projective geometry 5608:of an open segment 5404:triangle inequality 5380:projective geometry 5360:Projective geometry 4114:), is based on the 3868:Parametric equation 3862:Parametric equation 3847:{\displaystyle t=0} 2460:if it is not zero. 2241:coordinate geometry 2206:Perpendicular lines 1439:-dimensional space 478:Pythagorean theorem 6306:, pp. 13–19, 5992:Protter, Murray H. 5835:collineation group 5800:Generalised circle 5729: 5694: 5652:Euclidean geometry 5589:ray is called the 5440: 5378:In many models of 5376: 5331:incidence geometry 5298: 5228: 5192: 5172: 5118: 5080: 5036: 4988: 4928: 4881: 4853: 4786: 4720: 4645: 4614: 4536: 4471: 4451: 4425: 4368: 4335: 4313: 4244: 4194: 4174: 4100: 3993: 3991: 3844: 3818: 3717: 3658: 3599: 3519: 3432: 3371: 3285: 3245: 3196: 3093: 3046: 2884: 2755: 2640:may be written as 2630: 2574: 2504: 2397: 2314: 2302:affine coordinates 2298: 2265:Euclidean geometry 2200:Intersecting lines 2040: 2013:Manhattan distance 1914:Euclidean distance 1910:Euclidean geometry 1871: 1865: 1618:affine coordinates 1545: 1285:Euclidean geometry 1243:one, which may be 56: 6417:Analytic geometry 6313:978-0-495-56521-5 6296:Stewart, James B. 5972:Russell, Bertrand 5951:Padoa, Alessandro 5929:978-1-4411-3724-1 5833:Technically, the 5745:imaginary numbers 5384:elliptic geometry 5323:analytic geometry 5277: 5261: 4983: 4781: 4653:polar coordinates 4635:Polar coordinates 4396:), one drops the 4308: 4281: 4112:Ludwig Otto Hesse 4108:Hesse normal form 4106:(also called the 4090:Hesse normal form 4084:Hesse normal form 3040: 2963: 2869: 2317:{\displaystyle L} 2261:Euclid's Elements 2237:axiomatic systems 2108:For more general 2063:), lines can be: 1423:in the variables 1392:if they are not. 1209: 1208: 1174: 1173: 897:List of geometers 580:Three-dimensional 569: 568: 16:(Redirected from 6434: 6389: 6362: 6361: 6327:Patterson, B. C. 6323: 6317: 6316: 6302:(5th ed.), 6292: 6286: 6285: 6268: 6262: 6261: 6244: 6238: 6237: 6220: 6214: 6213: 6192: 6186: 6185: 6168: 6162: 6161: 6150: 6140: 6134: 6133: 6101:College Geometry 6096: 6090: 6078: 6061: 6055: 6054: 6037: 6017: 6011: 6010: 5988: 5982: 5981: 5968: 5962: 5961: 5947: 5941: 5940: 5913: 5907: 5906: 5889: 5859: 5848: 5842: 5831: 5810:Plane (geometry) 5619: 5307: 5305: 5304: 5299: 5278: 5275: 5262: 5259: 5237: 5235: 5234: 5229: 5205: 5201: 5199: 5198: 5193: 5181: 5179: 5178: 5173: 5127: 5125: 5124: 5119: 5089: 5087: 5086: 5081: 5045: 5043: 5042: 5037: 5004: 4997: 4995: 4994: 4989: 4984: 4982: 4956: 4941: 4937: 4935: 4934: 4929: 4924: 4894: 4890: 4888: 4887: 4882: 4866: 4862: 4860: 4859: 4854: 4849: 4823: 4802: 4795: 4793: 4792: 4787: 4782: 4780: 4754: 4740:—can be written 4739: 4729: 4727: 4726: 4721: 4665: 4623: 4621: 4620: 4615: 4610: 4602: 4588: 4580: 4545: 4543: 4542: 4537: 4535: 4520: 4509: 4484: 4480: 4478: 4477: 4472: 4460: 4458: 4457: 4452: 4434: 4432: 4431: 4426: 4409:term to compute 4408: 4406: 4395: 4384: 4377: 4375: 4374: 4369: 4357: 4350: 4344: 4342: 4341: 4336: 4322: 4320: 4319: 4314: 4309: 4307: 4306: 4294: 4293: 4284: 4282: 4280: 4279: 4271: 4262: 4253: 4251: 4250: 4245: 4215: 4209: 4203: 4201: 4200: 4195: 4183: 4181: 4180: 4175: 4002: 4000: 3999: 3994: 3992: 3979: 3978: 3946: 3945: 3913: 3912: 3874:three dimensions 3853: 3851: 3850: 3845: 3827: 3825: 3824: 3819: 3817: 3816: 3801: 3800: 3788: 3787: 3772: 3771: 3759: 3758: 3743: 3742: 3726: 3724: 3723: 3718: 3713: 3712: 3700: 3699: 3687: 3686: 3667: 3665: 3664: 3659: 3654: 3653: 3641: 3640: 3628: 3627: 3608: 3606: 3605: 3600: 3592: 3591: 3576: 3575: 3560: 3559: 3544: 3543: 3528: 3526: 3525: 3520: 3512: 3511: 3496: 3495: 3480: 3479: 3464: 3463: 3447:linear equations 3441: 3439: 3438: 3433: 3431: 3430: 3415: 3414: 3380: 3378: 3377: 3372: 3367: 3366: 3354: 3353: 3341: 3333: 3332: 3320: 3319: 3294: 3292: 3291: 3286: 3284: 3283: 3271: 3270: 3254: 3252: 3251: 3246: 3241: 3240: 3228: 3227: 3205: 3203: 3202: 3197: 3192: 3191: 3179: 3178: 3152: 3138:of the function 3102: 3100: 3099: 3094: 3055: 3053: 3052: 3047: 3041: 3039: 3038: 3037: 3025: 3024: 3014: 3013: 3012: 3003: 3002: 2990: 2989: 2980: 2979: 2969: 2964: 2962: 2961: 2960: 2948: 2947: 2937: 2936: 2935: 2923: 2922: 2912: 2893: 2891: 2890: 2885: 2883: 2882: 2870: 2868: 2867: 2866: 2854: 2853: 2843: 2842: 2841: 2829: 2828: 2818: 2812: 2811: 2780: 2764: 2762: 2761: 2756: 2748: 2747: 2726: 2725: 2713: 2712: 2694: 2693: 2681: 2680: 2665: 2664: 2639: 2637: 2636: 2631: 2626: 2625: 2613: 2612: 2600: 2599: 2583: 2581: 2580: 2575: 2570: 2569: 2557: 2556: 2544: 2543: 2513: 2511: 2510: 2505: 2459: 2455: 2448: 2406: 2404: 2403: 2398: 2323: 2321: 2320: 2315: 2277:Line coordinates 2233:primitive notion 2133:With respect to 2110:algebraic curves 2020:primitive notion 1880: 1878: 1877: 1872: 1870: 1869: 1862: 1861: 1845: 1844: 1833: 1832: 1814: 1813: 1797: 1796: 1785: 1784: 1766: 1765: 1749: 1748: 1737: 1736: 1595:Collinear points 1554: 1552: 1551: 1546: 1541: 1537: 1536: 1453:In more general 1339:primitive notion 1201: 1194: 1187: 915: 914: 434: 433: 367:Zero-dimensional 72: 58: 57: 21: 6442: 6441: 6437: 6436: 6435: 6433: 6432: 6431: 6427:Line (geometry) 6402: 6401: 6374: 6371: 6366: 6365: 6343:10.2307/2303867 6324: 6320: 6314: 6300:College Algebra 6293: 6289: 6269: 6265: 6259: 6245: 6241: 6235: 6221: 6217: 6211: 6203:, p. 314, 6193: 6189: 6169: 6165: 6159: 6141: 6137: 6115: 6107:, p. 114, 6097: 6093: 6076: 6062: 6058: 6044:10.2307/2690881 6018: 6014: 6008: 5989: 5985: 5969: 5965: 5948: 5944: 5930: 5914: 5910: 5904: 5890: 5873: 5868: 5863: 5862: 5849: 5845: 5832: 5828: 5823: 5785:Flat (geometry) 5761: 5753:complex numbers 5721: 5715: 5686: 5680: 5668:complex numbers 5656:affine geometry 5609: 5549:is not between 5432: 5425: 5420: 5368: 5362: 5327:linear equation 5319: 5317:Geometric space 5313: 5274: 5258: 5243: 5240: 5239: 5211: 5208: 5207: 5203: 5187: 5184: 5183: 5155: 5152: 5151: 5095: 5092: 5091: 5057: 5054: 5053: 5010: 5007: 5006: 4999: 4960: 4955: 4947: 4944: 4943: 4939: 4920: 4903: 4900: 4899: 4892: 4876: 4873: 4872: 4864: 4845: 4819: 4808: 4805: 4804: 4797: 4758: 4753: 4745: 4742: 4741: 4737: 4675: 4672: 4671: 4666:are related to 4655: 4649:Cartesian plane 4637: 4606: 4598: 4584: 4576: 4574: 4571: 4570: 4528: 4513: 4505: 4503: 4500: 4499: 4496: 4491: 4482: 4466: 4463: 4462: 4440: 4437: 4436: 4414: 4411: 4410: 4402: 4397: 4386: 4379: 4363: 4360: 4359: 4352: 4346: 4330: 4327: 4326: 4302: 4298: 4289: 4285: 4283: 4275: 4267: 4266: 4261: 4259: 4256: 4255: 4221: 4218: 4217: 4211: 4205: 4189: 4186: 4185: 4130: 4127: 4126: 4092: 4086: 4045: 4038: 4031: 3990: 3989: 3974: 3970: 3963: 3957: 3956: 3941: 3937: 3930: 3924: 3923: 3908: 3904: 3897: 3890: 3888: 3885: 3884: 3870: 3864: 3833: 3830: 3829: 3812: 3808: 3796: 3792: 3783: 3779: 3767: 3763: 3754: 3750: 3738: 3734: 3732: 3729: 3728: 3708: 3704: 3695: 3691: 3682: 3678: 3673: 3670: 3669: 3649: 3645: 3636: 3632: 3623: 3619: 3614: 3611: 3610: 3587: 3583: 3571: 3567: 3555: 3551: 3539: 3535: 3533: 3530: 3529: 3507: 3503: 3491: 3487: 3475: 3471: 3459: 3455: 3453: 3450: 3449: 3426: 3422: 3410: 3406: 3386: 3383: 3382: 3362: 3358: 3349: 3345: 3337: 3328: 3324: 3315: 3311: 3300: 3297: 3296: 3279: 3275: 3266: 3262: 3260: 3257: 3256: 3236: 3232: 3223: 3219: 3211: 3208: 3207: 3187: 3183: 3174: 3170: 3162: 3159: 3158: 3139: 3073: 3070: 3069: 3033: 3029: 3020: 3016: 3015: 3008: 3004: 2998: 2994: 2985: 2981: 2975: 2971: 2970: 2968: 2956: 2952: 2943: 2939: 2938: 2931: 2927: 2918: 2914: 2913: 2911: 2899: 2896: 2895: 2878: 2874: 2862: 2858: 2849: 2845: 2844: 2837: 2833: 2824: 2820: 2819: 2817: 2807: 2803: 2786: 2783: 2782: 2779: 2772: 2766: 2743: 2739: 2721: 2717: 2708: 2704: 2689: 2685: 2676: 2672: 2660: 2656: 2645: 2642: 2641: 2621: 2617: 2608: 2604: 2595: 2591: 2589: 2586: 2585: 2565: 2561: 2552: 2548: 2539: 2535: 2533: 2530: 2529: 2472: 2469: 2468: 2457: 2450: 2443: 2341: 2338: 2337: 2309: 2306: 2305: 2290: 2288:Linear equation 2284: 2282:Linear equation 2279: 2273: 2229: 2091:coordinate line 2032: 1864: 1863: 1857: 1853: 1851: 1846: 1840: 1836: 1834: 1828: 1824: 1822: 1816: 1815: 1809: 1805: 1803: 1798: 1792: 1788: 1786: 1780: 1776: 1774: 1768: 1767: 1761: 1757: 1755: 1750: 1744: 1740: 1738: 1732: 1728: 1726: 1716: 1715: 1713: 1710: 1709: 1704: 1695: 1688: 1677: 1668: 1661: 1650: 1641: 1634: 1603: 1597: 1532: 1494: 1490: 1482: 1479: 1478: 1455:Euclidean space 1413: 1401:convex polygons 1397:Euclidean plane 1306: 1298:affine geometry 1205: 1176: 1175: 912: 911: 902: 901: 692: 691: 675: 674: 660: 659: 647: 646: 583: 582: 571: 570: 431: 430: 428:Two-dimensional 419: 418: 392: 391: 389:One-dimensional 380: 379: 370: 369: 358: 357: 291: 290: 289: 272: 271: 120: 119: 108: 85: 41: 34:Line (graphics) 28: 23: 22: 15: 12: 11: 5: 6440: 6430: 6429: 6424: 6419: 6414: 6400: 6399: 6390: 6376:"Line (curve)" 6370: 6369:External links 6367: 6364: 6363: 6337:(9): 589–599, 6318: 6312: 6287: 6263: 6257: 6239: 6233: 6215: 6209: 6187: 6172:Bôcher, Maxime 6163: 6157: 6135: 6114:978-0030731006 6113: 6091: 6074: 6056: 6028:(3): 183–192, 6012: 6006: 5983: 5963: 5942: 5928: 5908: 5902: 5870: 5869: 5867: 5864: 5861: 5860: 5843: 5825: 5824: 5822: 5819: 5818: 5817: 5812: 5807: 5802: 5797: 5792: 5787: 5782: 5777: 5772: 5767: 5760: 5757: 5741:imaginary line 5717:Main article: 5714: 5711: 5682:Main article: 5679: 5676: 5620:and two rays, 5606:disjoint union 5573:determined by 5458:is called its 5454:and the point 5424: 5421: 5419: 5416: 5361: 5358: 5312: 5309: 5297: 5294: 5291: 5288: 5285: 5282: 5272: 5269: 5266: 5256: 5253: 5250: 5247: 5227: 5224: 5221: 5218: 5215: 5191: 5171: 5168: 5165: 5162: 5159: 5145:right triangle 5117: 5114: 5111: 5108: 5105: 5102: 5099: 5079: 5076: 5073: 5070: 5067: 5064: 5061: 5035: 5032: 5029: 5026: 5023: 5020: 5017: 5014: 4987: 4981: 4978: 4975: 4972: 4969: 4966: 4963: 4959: 4954: 4951: 4927: 4923: 4919: 4916: 4913: 4910: 4907: 4880: 4852: 4848: 4844: 4841: 4838: 4835: 4832: 4829: 4826: 4822: 4818: 4815: 4812: 4785: 4779: 4776: 4773: 4770: 4767: 4764: 4761: 4757: 4752: 4749: 4719: 4716: 4713: 4710: 4707: 4704: 4701: 4697: 4694: 4691: 4688: 4685: 4682: 4679: 4636: 4633: 4613: 4609: 4605: 4601: 4597: 4594: 4591: 4587: 4583: 4579: 4546:(where λ is a 4534: 4531: 4526: 4523: 4519: 4516: 4512: 4508: 4495: 4492: 4490: 4487: 4470: 4450: 4447: 4444: 4424: 4421: 4418: 4367: 4334: 4312: 4305: 4301: 4297: 4292: 4288: 4278: 4274: 4270: 4265: 4243: 4240: 4237: 4234: 4231: 4228: 4225: 4193: 4173: 4170: 4167: 4164: 4161: 4158: 4155: 4152: 4149: 4146: 4143: 4140: 4137: 4134: 4088:Main article: 4085: 4082: 4078: 4077: 4047: 4043: 4036: 4029: 4023: 3988: 3985: 3982: 3977: 3973: 3969: 3966: 3964: 3962: 3959: 3958: 3955: 3952: 3949: 3944: 3940: 3936: 3933: 3931: 3929: 3926: 3925: 3922: 3919: 3916: 3911: 3907: 3903: 3900: 3898: 3896: 3893: 3892: 3863: 3860: 3843: 3840: 3837: 3815: 3811: 3807: 3804: 3799: 3795: 3791: 3786: 3782: 3778: 3775: 3770: 3766: 3762: 3757: 3753: 3749: 3746: 3741: 3737: 3716: 3711: 3707: 3703: 3698: 3694: 3690: 3685: 3681: 3677: 3657: 3652: 3648: 3644: 3639: 3635: 3631: 3626: 3622: 3618: 3598: 3595: 3590: 3586: 3582: 3579: 3574: 3570: 3566: 3563: 3558: 3554: 3550: 3547: 3542: 3538: 3518: 3515: 3510: 3506: 3502: 3499: 3494: 3490: 3486: 3483: 3478: 3474: 3470: 3467: 3462: 3458: 3429: 3425: 3421: 3418: 3413: 3409: 3405: 3402: 3399: 3396: 3393: 3390: 3370: 3365: 3361: 3357: 3352: 3348: 3344: 3340: 3336: 3331: 3327: 3323: 3318: 3314: 3310: 3307: 3304: 3295:, is given by 3282: 3278: 3274: 3269: 3265: 3244: 3239: 3235: 3231: 3226: 3222: 3218: 3215: 3195: 3190: 3186: 3182: 3177: 3173: 3169: 3166: 3155: 3154: 3129: 3119: 3092: 3089: 3086: 3083: 3080: 3077: 3058:two dimensions 3045: 3036: 3032: 3028: 3023: 3019: 3011: 3007: 3001: 2997: 2993: 2988: 2984: 2978: 2974: 2967: 2959: 2955: 2951: 2946: 2942: 2934: 2930: 2926: 2921: 2917: 2909: 2906: 2903: 2881: 2877: 2873: 2865: 2861: 2857: 2852: 2848: 2840: 2836: 2832: 2827: 2823: 2815: 2810: 2806: 2802: 2799: 2796: 2793: 2790: 2777: 2770: 2754: 2751: 2746: 2742: 2738: 2735: 2732: 2729: 2724: 2720: 2716: 2711: 2707: 2703: 2700: 2697: 2692: 2688: 2684: 2679: 2675: 2671: 2668: 2663: 2659: 2655: 2652: 2649: 2629: 2624: 2620: 2616: 2611: 2607: 2603: 2598: 2594: 2573: 2568: 2564: 2560: 2555: 2551: 2547: 2542: 2538: 2503: 2500: 2497: 2494: 2491: 2488: 2485: 2482: 2479: 2476: 2396: 2393: 2390: 2387: 2384: 2381: 2378: 2375: 2372: 2369: 2366: 2363: 2360: 2357: 2354: 2351: 2348: 2345: 2313: 2286:Main article: 2283: 2280: 2275:Main article: 2272: 2269: 2228: 2225: 2196:Parallel lines 2160: 2159: 2153: 2146: 2131: 2130: 2124: 2095: 2094: 2087: 2080: 2077: 2071: 2031: 2028: 2009: 2008: 1868: 1860: 1856: 1852: 1850: 1847: 1843: 1839: 1835: 1831: 1827: 1823: 1821: 1818: 1817: 1812: 1808: 1804: 1802: 1799: 1795: 1791: 1787: 1783: 1779: 1775: 1773: 1770: 1769: 1764: 1760: 1756: 1754: 1751: 1747: 1743: 1739: 1735: 1731: 1727: 1725: 1722: 1721: 1719: 1700: 1693: 1686: 1673: 1666: 1659: 1646: 1639: 1632: 1599:Main article: 1596: 1593: 1544: 1540: 1535: 1531: 1528: 1525: 1522: 1519: 1516: 1513: 1509: 1506: 1503: 1500: 1497: 1493: 1489: 1486: 1477:is the subset 1412: 1409: 1333:(now called a 1323:(now called a 1305: 1302: 1279:Euclidean line 1207: 1206: 1204: 1203: 1196: 1189: 1181: 1178: 1177: 1172: 1171: 1170: 1169: 1164: 1156: 1155: 1151: 1150: 1149: 1148: 1143: 1138: 1133: 1128: 1123: 1118: 1113: 1108: 1103: 1098: 1090: 1089: 1085: 1084: 1083: 1082: 1077: 1072: 1067: 1062: 1057: 1052: 1047: 1039: 1038: 1034: 1033: 1032: 1031: 1026: 1021: 1016: 1011: 1006: 1001: 996: 991: 986: 981: 976: 968: 967: 963: 962: 961: 960: 955: 950: 945: 940: 935: 930: 922: 921: 913: 909: 908: 907: 904: 903: 900: 899: 894: 889: 884: 879: 874: 869: 864: 859: 854: 849: 844: 839: 834: 829: 824: 819: 814: 809: 804: 799: 794: 789: 784: 779: 774: 769: 764: 759: 754: 749: 744: 739: 734: 729: 724: 719: 714: 709: 704: 699: 693: 689: 688: 687: 684: 683: 677: 676: 673: 672: 667: 661: 654: 653: 652: 649: 648: 645: 644: 639: 634: 632:Platonic Solid 629: 624: 619: 614: 609: 604: 603: 602: 591: 590: 584: 578: 577: 576: 573: 572: 567: 566: 565: 564: 559: 554: 546: 545: 539: 538: 537: 536: 531: 523: 522: 516: 515: 514: 513: 508: 503: 498: 490: 489: 483: 482: 481: 480: 475: 470: 462: 461: 455: 454: 453: 452: 447: 442: 432: 426: 425: 424: 421: 420: 417: 416: 411: 410: 409: 404: 393: 387: 386: 385: 382: 381: 378: 377: 371: 365: 364: 363: 360: 359: 356: 355: 350: 345: 339: 338: 333: 328: 318: 313: 308: 302: 301: 292: 288: 287: 284: 280: 279: 278: 277: 274: 273: 270: 269: 268: 267: 257: 252: 247: 242: 237: 236: 235: 225: 220: 215: 214: 213: 208: 203: 193: 192: 191: 186: 176: 171: 166: 161: 156: 151: 150: 149: 144: 143: 142: 127: 121: 115: 114: 113: 110: 109: 107: 106: 96: 90: 87: 86: 73: 65: 64: 26: 9: 6: 4: 3: 2: 6439: 6428: 6425: 6423: 6420: 6418: 6415: 6413: 6410: 6409: 6407: 6398: 6394: 6391: 6387: 6383: 6382: 6377: 6373: 6372: 6360: 6356: 6352: 6348: 6344: 6340: 6336: 6332: 6328: 6322: 6315: 6309: 6305: 6301: 6297: 6291: 6284: 6280: 6279: 6274: 6267: 6260: 6258:0-486-65812-0 6254: 6250: 6243: 6236: 6234:0-07-072191-2 6230: 6226: 6219: 6212: 6210:9781139473736 6206: 6202: 6198: 6191: 6183: 6179: 6178: 6173: 6167: 6160: 6158:0-471-18283-4 6154: 6149: 6148: 6139: 6132: 6128: 6124: 6120: 6116: 6110: 6106: 6102: 6095: 6088: 6085:, p. 108, at 6084: 6083: 6077: 6075:9780883853481 6071: 6067: 6060: 6053: 6049: 6045: 6041: 6036: 6035:10.1.1.502.72 6031: 6027: 6023: 6016: 6009: 6007:9780867200935 6003: 5999: 5998: 5993: 5987: 5980:, p. 410 5979: 5978: 5973: 5967: 5960: 5957:(in French), 5956: 5952: 5946: 5939: 5935: 5931: 5925: 5921: 5920: 5912: 5905: 5903:0-8247-1748-1 5899: 5895: 5888: 5886: 5884: 5882: 5880: 5878: 5876: 5871: 5857: 5853: 5847: 5840: 5836: 5830: 5826: 5816: 5813: 5811: 5808: 5806: 5803: 5801: 5798: 5796: 5793: 5791: 5788: 5786: 5783: 5781: 5778: 5776: 5773: 5771: 5768: 5766: 5763: 5762: 5756: 5754: 5750: 5749:complex plane 5746: 5743:representing 5742: 5738: 5734: 5725: 5720: 5710: 5708: 5704: 5699: 5690: 5685: 5675: 5673: 5669: 5665: 5661: 5660:ordered field 5657: 5653: 5648: 5646: 5641: 5639: 5635: 5631: 5627: 5623: 5617: 5613: 5607: 5603: 5599: 5594: 5592: 5588: 5584: 5580: 5576: 5572: 5568: 5564: 5560: 5556: 5552: 5548: 5544: 5540: 5536: 5532: 5528: 5524: 5520: 5516: 5512: 5508: 5504: 5500: 5496: 5492: 5488: 5484: 5479: 5477: 5473: 5469: 5465: 5461: 5460:initial point 5457: 5453: 5449: 5445: 5436: 5430: 5415: 5413: 5412:metric spaces 5409: 5405: 5401: 5396: 5393: 5389: 5388:great circles 5385: 5381: 5372: 5367: 5357: 5355: 5351: 5347: 5343: 5339: 5334: 5332: 5328: 5324: 5318: 5308: 5295: 5292: 5289: 5286: 5283: 5280: 5270: 5267: 5264: 5254: 5251: 5248: 5245: 5222: 5219: 5216: 5189: 5166: 5163: 5160: 5148: 5146: 5142: 5138: 5137:geometrically 5133: 5131: 5115: 5112: 5109: 5106: 5103: 5100: 5097: 5077: 5074: 5071: 5068: 5065: 5062: 5059: 5051: 5046: 5033: 5030: 5027: 5024: 5021: 5018: 5015: 5012: 5002: 4985: 4976: 4973: 4970: 4964: 4961: 4957: 4952: 4949: 4925: 4921: 4917: 4914: 4911: 4908: 4905: 4896: 4878: 4870: 4850: 4846: 4842: 4839: 4836: 4833: 4830: 4827: 4824: 4820: 4816: 4813: 4810: 4800: 4783: 4774: 4771: 4768: 4762: 4759: 4755: 4750: 4747: 4735: 4730: 4717: 4714: 4711: 4708: 4705: 4702: 4699: 4695: 4692: 4689: 4686: 4683: 4680: 4677: 4669: 4663: 4659: 4654: 4650: 4641: 4632: 4630: 4625: 4603: 4592: 4589: 4581: 4568: 4564: 4560: 4556: 4551: 4549: 4524: 4521: 4510: 4486: 4468: 4448: 4445: 4442: 4422: 4419: 4416: 4405: 4400: 4393: 4389: 4383: 4365: 4355: 4349: 4332: 4323: 4310: 4303: 4299: 4295: 4290: 4286: 4272: 4263: 4241: 4238: 4235: 4232: 4229: 4226: 4223: 4214: 4208: 4191: 4171: 4168: 4165: 4162: 4159: 4156: 4153: 4150: 4147: 4144: 4141: 4138: 4135: 4132: 4124: 4120: 4118: 4113: 4109: 4105: 4096: 4091: 4081: 4075: 4071: 4067: 4063: 4059: 4055: 4051: 4048: 4042: 4035: 4028: 4024: 4021: 4017: 4013: 4009: 4006: 4005: 4004: 3986: 3983: 3980: 3975: 3971: 3967: 3965: 3960: 3953: 3950: 3947: 3942: 3938: 3934: 3932: 3927: 3920: 3917: 3914: 3909: 3905: 3901: 3899: 3894: 3881: 3879: 3875: 3869: 3859: 3857: 3841: 3838: 3835: 3813: 3809: 3805: 3802: 3797: 3793: 3789: 3784: 3780: 3776: 3773: 3768: 3764: 3760: 3755: 3751: 3747: 3744: 3739: 3735: 3709: 3705: 3701: 3696: 3692: 3688: 3683: 3679: 3650: 3646: 3642: 3637: 3633: 3629: 3624: 3620: 3596: 3593: 3588: 3584: 3580: 3577: 3572: 3568: 3564: 3561: 3556: 3552: 3548: 3545: 3540: 3536: 3516: 3513: 3508: 3504: 3500: 3497: 3492: 3488: 3484: 3481: 3476: 3472: 3468: 3465: 3460: 3456: 3448: 3443: 3427: 3423: 3419: 3411: 3407: 3403: 3400: 3394: 3391: 3388: 3363: 3359: 3355: 3350: 3346: 3338: 3329: 3325: 3321: 3316: 3312: 3305: 3302: 3280: 3276: 3272: 3267: 3263: 3237: 3233: 3229: 3224: 3220: 3213: 3188: 3184: 3180: 3175: 3171: 3164: 3150: 3146: 3142: 3137: 3133: 3130: 3127: 3123: 3120: 3117: 3113: 3109: 3106: 3105: 3104: 3090: 3087: 3084: 3081: 3078: 3075: 3067: 3065: 3064: 3059: 3043: 3034: 3030: 3026: 3021: 3017: 3009: 3005: 2999: 2995: 2991: 2986: 2982: 2976: 2972: 2965: 2957: 2953: 2949: 2944: 2940: 2932: 2928: 2924: 2919: 2915: 2907: 2904: 2901: 2879: 2875: 2871: 2863: 2859: 2855: 2850: 2846: 2838: 2834: 2830: 2825: 2821: 2808: 2804: 2800: 2797: 2791: 2788: 2776: 2769: 2752: 2744: 2740: 2736: 2733: 2722: 2718: 2714: 2709: 2705: 2698: 2690: 2686: 2682: 2677: 2673: 2661: 2657: 2653: 2650: 2622: 2618: 2614: 2609: 2605: 2596: 2592: 2566: 2562: 2558: 2553: 2549: 2540: 2536: 2526: 2524: 2519: 2517: 2501: 2498: 2495: 2492: 2489: 2486: 2483: 2480: 2477: 2474: 2466: 2465:standard form 2461: 2453: 2446: 2440: 2438: 2434: 2430: 2426: 2422: 2418: 2414: 2410: 2394: 2388: 2385: 2382: 2379: 2376: 2373: 2370: 2367: 2361: 2358: 2355: 2346: 2343: 2335: 2331: 2327: 2311: 2303: 2294: 2289: 2278: 2268: 2266: 2262: 2257: 2253: 2248: 2246: 2242: 2238: 2234: 2224: 2222: 2218: 2213: 2211: 2207: 2203: 2201: 2197: 2193: 2191: 2187: 2183: 2178: 2176: 2172: 2168: 2167:quadrilateral 2165: 2157: 2156:central lines 2154: 2151: 2147: 2144: 2140: 2139: 2138: 2136: 2128: 2125: 2122: 2118: 2115: 2114: 2113: 2111: 2106: 2104: 2100: 2092: 2088: 2085: 2081: 2078: 2075: 2072: 2069: 2068:tangent lines 2066: 2065: 2064: 2062: 2058: 2054: 2050: 2046: 2036: 2027: 2025: 2021: 2016: 2014: 2006: 2002: 1998: 1994: 1990: 1986: 1982: 1978: 1974: 1970: 1966: 1962: 1958: 1954: 1950: 1946: 1942: 1938: 1937: 1936: 1934: 1930: 1926: 1922: 1918: 1915: 1911: 1906: 1904: 1900: 1894: 1892: 1888: 1884: 1866: 1858: 1854: 1848: 1841: 1837: 1829: 1825: 1819: 1810: 1806: 1800: 1793: 1789: 1781: 1777: 1771: 1762: 1758: 1752: 1745: 1741: 1733: 1729: 1723: 1717: 1708: 1703: 1699: 1692: 1685: 1681: 1676: 1672: 1665: 1658: 1654: 1649: 1645: 1638: 1631: 1627: 1623: 1619: 1614: 1612: 1608: 1602: 1592: 1590: 1586: 1582: 1579: −  1578: 1574: 1570: 1566: 1562: 1558: 1542: 1538: 1529: 1526: 1523: 1520: 1517: 1514: 1511: 1504: 1501: 1498: 1491: 1487: 1484: 1476: 1472: 1468: 1464: 1460: 1456: 1451: 1449: 1446: 1442: 1438: 1434: 1430: 1426: 1422: 1418: 1408: 1406: 1402: 1398: 1393: 1391: 1387: 1383: 1379: 1375: 1371: 1367: 1362: 1360: 1356: 1352: 1348: 1344: 1340: 1336: 1332: 1331:straight line 1328: 1327: 1322: 1318: 1317: 1311: 1301: 1299: 1295: 1291: 1290:non-Euclidean 1287: 1286: 1281: 1280: 1275: 1271: 1270: 1264: 1262: 1258: 1254: 1250: 1246: 1242: 1238: 1234: 1230: 1226: 1222: 1218: 1217:straight line 1214: 1202: 1197: 1195: 1190: 1188: 1183: 1182: 1180: 1179: 1168: 1165: 1163: 1160: 1159: 1158: 1157: 1153: 1152: 1147: 1144: 1142: 1139: 1137: 1134: 1132: 1129: 1127: 1124: 1122: 1119: 1117: 1114: 1112: 1109: 1107: 1104: 1102: 1099: 1097: 1094: 1093: 1092: 1091: 1087: 1086: 1081: 1078: 1076: 1073: 1071: 1068: 1066: 1063: 1061: 1058: 1056: 1053: 1051: 1048: 1046: 1043: 1042: 1041: 1040: 1036: 1035: 1030: 1027: 1025: 1022: 1020: 1017: 1015: 1012: 1010: 1007: 1005: 1002: 1000: 997: 995: 992: 990: 987: 985: 982: 980: 977: 975: 972: 971: 970: 969: 965: 964: 959: 956: 954: 951: 949: 946: 944: 941: 939: 936: 934: 931: 929: 926: 925: 924: 923: 920: 917: 916: 906: 905: 898: 895: 893: 890: 888: 885: 883: 880: 878: 875: 873: 870: 868: 865: 863: 860: 858: 855: 853: 850: 848: 845: 843: 840: 838: 835: 833: 830: 828: 825: 823: 820: 818: 815: 813: 810: 808: 805: 803: 800: 798: 795: 793: 790: 788: 785: 783: 780: 778: 775: 773: 770: 768: 765: 763: 760: 758: 755: 753: 750: 748: 745: 743: 740: 738: 735: 733: 730: 728: 725: 723: 720: 718: 715: 713: 710: 708: 705: 703: 700: 698: 695: 694: 686: 685: 682: 679: 678: 671: 668: 666: 663: 662: 657: 651: 650: 643: 640: 638: 635: 633: 630: 628: 625: 623: 620: 618: 615: 613: 610: 608: 605: 601: 598: 597: 596: 593: 592: 589: 586: 585: 581: 575: 574: 563: 560: 558: 557:Circumference 555: 553: 550: 549: 548: 547: 544: 541: 540: 535: 532: 530: 527: 526: 525: 524: 521: 520:Quadrilateral 518: 517: 512: 509: 507: 504: 502: 499: 497: 494: 493: 492: 491: 488: 487:Parallelogram 485: 484: 479: 476: 474: 471: 469: 466: 465: 464: 463: 460: 457: 456: 451: 448: 446: 443: 441: 438: 437: 436: 435: 429: 423: 422: 415: 412: 408: 405: 403: 400: 399: 398: 395: 394: 390: 384: 383: 376: 373: 372: 368: 362: 361: 354: 351: 349: 346: 344: 341: 340: 337: 334: 332: 329: 326: 325:Perpendicular 322: 321:Orthogonality 319: 317: 314: 312: 309: 307: 304: 303: 300: 297: 296: 295: 285: 282: 281: 276: 275: 266: 263: 262: 261: 258: 256: 253: 251: 248: 246: 245:Computational 243: 241: 238: 234: 231: 230: 229: 226: 224: 221: 219: 216: 212: 209: 207: 204: 202: 199: 198: 197: 194: 190: 187: 185: 182: 181: 180: 177: 175: 172: 170: 167: 165: 162: 160: 157: 155: 152: 148: 145: 141: 138: 137: 136: 133: 132: 131: 130:Non-Euclidean 128: 126: 123: 122: 118: 112: 111: 104: 100: 97: 95: 92: 91: 89: 88: 84: 80: 76: 71: 67: 66: 63: 60: 59: 54: 50: 45: 39: 35: 30: 19: 18:Straight line 6397:Cut-the-Knot 6379: 6334: 6330: 6321: 6299: 6290: 6276: 6266: 6248: 6242: 6224: 6218: 6196: 6190: 6176: 6166: 6146: 6138: 6103:, New York: 6100: 6094: 6087:Google Books 6080: 6065: 6059: 6025: 6021: 6015: 5996: 5986: 5975: 5966: 5954: 5945: 5918: 5911: 5893: 5855: 5851: 5846: 5839:transitively 5829: 5795:Line segment 5730: 5698:line segment 5695: 5684:Line segment 5678:Line segment 5672:finite field 5649: 5642: 5637: 5636:on the line 5633: 5629: 5625: 5621: 5615: 5611: 5601: 5597: 5595: 5591:opposite ray 5590: 5586: 5582: 5578: 5574: 5570: 5566: 5562: 5558: 5554: 5550: 5546: 5542: 5538: 5534: 5530: 5526: 5522: 5518: 5514: 5510: 5506: 5502: 5498: 5494: 5490: 5486: 5482: 5480: 5475: 5471: 5463: 5459: 5455: 5451: 5447: 5443: 5441: 5397: 5377: 5335: 5320: 5149: 5139:by applying 5134: 5047: 5000: 4938:between the 4897: 4869:line segment 4798: 4731: 4661: 4657: 4646: 4628: 4626: 4566: 4562: 4558: 4554: 4552: 4497: 4403: 4398: 4391: 4387: 4381: 4353: 4347: 4324: 4212: 4206: 4115: 4107: 4103: 4101: 4079: 4073: 4069: 4065: 4057: 4053: 4049: 4040: 4033: 4026: 4019: 4015: 4011: 4007: 3882: 3877: 3871: 3444: 3156: 3148: 3144: 3140: 3131: 3128:of the line. 3121: 3118:of the line. 3107: 3068: 3061: 2774: 2767: 2527: 2520: 2516:general form 2515: 2464: 2462: 2451: 2444: 2441: 2436: 2432: 2428: 2427:) such that 2425:coefficients 2421:real numbers 2416: 2412: 2408: 2333: 2329: 2299: 2256:mental image 2255: 2251: 2249: 2230: 2214: 2210:right angles 2204: 2194: 2179: 2161: 2150:Simson lines 2132: 2120: 2116: 2107: 2096: 2074:secant lines 2041: 2017: 2010: 2004: 2000: 1996: 1992: 1988: 1984: 1980: 1976: 1972: 1968: 1964: 1960: 1956: 1952: 1948: 1944: 1940: 1932: 1928: 1924: 1920: 1916: 1907: 1902: 1898: 1895: 1886: 1701: 1697: 1690: 1683: 1679: 1674: 1670: 1663: 1656: 1652: 1647: 1643: 1636: 1629: 1625: 1621: 1615: 1606: 1604: 1601:Collinearity 1588: 1584: 1580: 1576: 1572: 1568: 1564: 1560: 1474: 1470: 1466: 1465:), the line 1463:affine space 1458: 1452: 1444: 1440: 1436: 1432: 1428: 1424: 1414: 1394: 1363: 1355:analytically 1351:real numbers 1335:line segment 1330: 1324: 1320: 1319:, a general 1315: 1307: 1283: 1278: 1277: 1268: 1265: 1260: 1253:line segment 1248: 1235:. Lines are 1233:ray of light 1229:straightedge 1220: 1216: 1210: 1029:Parameshvara 842:Parameshvara 612:Dodecahedron 396: 196:Differential 29: 6304:Brooks Cole 6082:online copy 5733:real number 5719:Number line 5713:Number line 5628:(the point 5525:is between 5501:(including 5238:such that 5050:normal form 4104:normal form 3126:y-intercept 2523:x-intercept 2326:coordinates 2252:description 2190:Pappus line 2186:Pascal line 2171:Newton line 2103:transversal 2099:parallelism 1939:The points 1891:determinant 1359:coordinates 1154:Present day 1101:Lobachevsky 1088:1700s–1900s 1045:Jyeṣṭhadeva 1037:1400s–1700s 989:Brahmagupta 812:Lobachevsky 792:Jyeṣṭhadeva 742:Brahmagupta 670:Hypersphere 642:Tetrahedron 617:Icosahedron 189:Diophantine 6406:Categories 5866:References 5557:. A point 5545:such that 5521:such that 5468:half-space 5418:Extensions 5315:See also: 4565:is vector 4557:is vector 3609:such that 2419:are fixed 2271:Definition 2221:skew lines 2143:Euler line 2127:asymptotes 1999:) implies 1448:coordinate 1374:dimensions 1304:Properties 1294:projective 1274:postulates 1014:al-Yasamin 958:Apollonius 953:Archimedes 943:Pythagoras 933:Baudhayana 887:al-Yasamin 837:Pythagoras 732:Baudhayana 722:Archimedes 717:Apollonius 622:Octahedron 473:Hypotenuse 348:Similarity 343:Congruence 255:Incidence 206:Symplectic 201:Riemannian 184:Arithmetic 159:Projective 147:Hyperbolic 75:Projecting 6386:EMS Press 6283:EMS Press 6030:CiteSeerX 5938:747274805 5707:collinear 5585:ray, the 5464:half-line 5408:geodesics 5342:primitive 5293:π 5287:α 5281:θ 5271:α 5265:θ 5249:≥ 5223:θ 5202:with the 5190:α 5167:θ 5113:θ 5110:⁡ 5075:θ 5072:⁡ 5031:π 5025:α 5019:θ 4977:α 4974:− 4971:θ 4965:⁡ 4918:π 4912:φ 4906:α 4879:φ 4843:π 4837:φ 4831:θ 4817:π 4814:− 4811:φ 4775:φ 4772:− 4769:θ 4763:⁡ 4715:θ 4712:⁡ 4693:θ 4690:⁡ 4604:− 4593:λ 4525:λ 4469:φ 4449:φ 4446:⁡ 4423:φ 4420:⁡ 4366:φ 4333:φ 4192:φ 4160:− 4157:φ 4154:⁡ 4142:φ 4139:⁡ 3581:− 3501:− 3404:− 3356:− 3322:− 3273:≠ 3027:− 2992:− 2950:− 2925:− 2856:− 2831:− 2801:− 2737:− 2715:− 2683:− 2654:− 2490:− 2368:∣ 2175:diagonals 2137:we have: 2135:triangles 2084:directrix 2061:hyperbola 1893:is zero. 1849:⋯ 1801:⋯ 1753:⋯ 1607:collinear 1557:direction 1530:∈ 1524:∣ 1502:− 1314:Euclid's 1267:Euclid's 1261:endpoints 1241:dimension 1225:curvature 1131:Minkowski 1050:Descartes 984:Aryabhata 979:Kātyāyana 910:by period 822:Minkowski 797:Kātyāyana 757:Descartes 702:Aryabhata 681:Geometers 665:Tesseract 529:Trapezoid 501:Rectangle 294:Dimension 179:Algebraic 169:Synthetic 140:Spherical 125:Euclidean 6422:Infinity 6182:archived 6174:(1915), 6123:69-12075 5953:(1900), 5815:Polyline 5759:See also 5737:integers 5703:coplanar 5658:over an 5400:distance 5366:Geodesic 5350:geodesic 3116:gradient 2423:(called 2057:parabola 1382:parallel 1316:Elements 1269:Elements 1245:embedded 1213:geometry 1121:Poincaré 1065:Minggatu 1024:Yang Hui 994:Virasena 882:Yang Hui 877:Virasena 847:Poincaré 827:Minggatu 607:Cylinder 552:Diameter 511:Rhomboid 468:Altitude 459:Triangle 353:Symmetry 331:Parallel 316:Diagonal 286:Features 283:Concepts 174:Analytic 135:Elliptic 117:Branches 103:Timeline 62:Geometry 6388:, 2001 6359:0006034 6351:2303867 6273:"Angle" 6052:2690881 5670:or any 4494:Vectors 4401:/| 4358:, then 4119:segment 4003:where: 3255:, when 3134:is the 3124:is the 3110:is the 3103:where: 2182:hexagon 2053:ellipse 1696:, ..., 1678:), and 1669:, ..., 1642:, ..., 1366:Hilbert 1308:In the 1146:Coxeter 1126:Hilbert 1111:Riemann 1060:Huygens 1019:al-Tusi 1009:Khayyám 999:Alhazen 966:1–1400s 867:al-Tusi 852:Riemann 802:Khayyám 787:Huygens 782:Hilbert 752:Coxeter 712:Alhazen 690:by name 627:Pyramid 506:Rhombus 450:Polygon 402:segment 250:Fractal 233:Digital 218:Complex 99:History 94:Outline 6357:  6349:  6310:  6255:  6231:  6207:  6155:  6129:  6121:  6111:  6072:  6050:  6032:  6004:  5936:  5926:  5900:  5856:closed 5392:planes 5338:axioms 5003:> 0 4863:Here, 4801:> 0 4738:(0, 0) 4734:origin 4548:scalar 4407:| 4356:> 0 4184:where 4123:origin 4117:normal 4062:vector 4056:, and 4014:, and 3878:cannot 3828:imply 2407:where 2245:axioms 2180:For a 2164:convex 2162:For a 2049:circle 1975:) and 1912:, the 1881:has a 1707:matrix 1431:, and 1370:points 1343:axioms 1296:, and 1257:points 1237:spaces 1167:Gromov 1162:Atiyah 1141:Veblen 1136:Cartan 1106:Bolyai 1075:Sakabe 1055:Pascal 948:Euclid 938:Manava 872:Veblen 857:Sakabe 832:Pascal 817:Manava 777:Gromov 762:Euclid 747:Cartan 737:Bolyai 727:Atiyah 637:Sphere 600:cuboid 588:Volume 543:Circle 496:Square 414:Length 336:Vertex 240:Convex 223:Finite 164:Affine 79:sphere 49:origin 6347:JSTOR 6131:47870 6048:JSTOR 5837:acts 5821:Notes 5805:Locus 5770:Curve 5645:angle 4998:with 4796:with 4647:In a 3856:plane 3112:slope 2439:= 0. 2152:, and 2059:, or 2045:conic 2043:to a 2030:Types 1620:, in 1611:plane 1395:On a 1388:, or 1386:plane 1378:plane 1326:curve 1310:Greek 1259:(its 1116:Klein 1096:Gauss 1070:Euler 1004:Sijzi 974:Zhang 928:Ahmes 892:Zhang 862:Sijzi 807:Klein 772:Gauss 767:Euler 707:Ahmes 440:Plane 375:Point 311:Curve 306:Angle 83:plane 81:to a 6308:ISBN 6253:ISBN 6229:ISBN 6205:ISBN 6153:ISBN 6127:OCLC 6119:LCCN 6109:ISBN 6070:ISBN 6002:ISBN 5934:OCLC 5924:ISBN 5898:ISBN 5852:open 5624:and 5600:and 5565:and 5553:and 5541:and 5529:and 5517:and 5505:and 5497:and 5485:and 5090:and 5022:< 5016:< 5005:and 4834:< 4828:< 4803:and 4561:and 4435:and 4345:and 4102:The 3668:and 3206:and 2584:and 2431:and 2415:and 2148:the 2141:the 1987:) = 1963:) = 1947:and 1931:and 1883:rank 1587:and 1555:The 1473:and 1419:, a 1390:skew 1321:line 1282:and 1249:line 1221:line 1215:, a 1080:Aida 697:Aida 656:Four 595:Cube 562:Area 534:Kite 445:Area 397:Line 38:Line 6395:at 6339:doi 6040:doi 5654:or 5452:ray 5423:Ray 5410:in 5260:and 5107:sin 5069:cos 4962:sin 4760:cos 4709:sin 4687:cos 4553:If 4550:). 4443:cos 4417:sin 4394:= 0 4151:sin 4136:cos 3114:or 3056:In 2894:or 2765:If 2454:= 0 2449:or 2447:= 1 2254:or 2235:in 2215:In 2047:(a 1908:In 1682:= ( 1655:= ( 1651:), 1628:= ( 1616:In 1415:In 1347:set 1263:). 1239:of 1211:In 919:BCE 407:ray 6408:: 6384:, 6378:, 6355:MR 6353:, 6345:, 6335:48 6333:, 6281:, 6275:, 6199:, 6125:, 6117:, 6046:, 6038:, 6026:72 6024:, 5974:, 5932:, 5874:^ 5755:. 5709:. 5696:A 5674:. 5647:. 5638:AB 5626:AD 5622:BC 5614:, 5593:. 5587:AD 5583:AB 5414:. 5276:or 4851:2. 4660:, 4651:, 4624:. 4567:OB 4559:OA 4485:. 4390:= 4072:, 4068:, 4052:, 4039:, 4032:, 4010:, 3442:. 3143:= 3066:: 2773:≠ 2411:, 2332:, 2219:, 2212:. 2192:. 2177:. 2089:a 2082:a 2055:, 2051:, 2003:= 1943:, 1689:, 1662:, 1635:, 1457:, 1427:, 1407:. 1361:. 1300:. 1292:, 77:a 6341:: 6089:) 6079:( 6042:: 5858:. 5634:A 5630:D 5618:) 5616:B 5612:A 5610:( 5602:B 5598:A 5579:A 5575:B 5571:A 5567:B 5563:A 5559:D 5555:C 5551:B 5547:A 5543:B 5539:A 5535:C 5531:C 5527:A 5523:B 5519:B 5515:A 5511:C 5507:B 5503:A 5499:B 5495:A 5491:A 5487:B 5483:A 5476:A 5472:A 5456:A 5448:A 5444:A 5431:. 5296:. 5290:+ 5284:= 5268:= 5255:, 5252:0 5246:r 5226:) 5220:, 5217:r 5214:( 5204:x 5170:) 5164:, 5161:r 5158:( 5116:, 5104:r 5101:= 5098:y 5078:, 5066:r 5063:= 5060:x 5034:. 5028:+ 5013:0 5001:r 4986:, 4980:) 4968:( 4958:p 4953:= 4950:r 4940:x 4926:2 4922:/ 4915:+ 4909:= 4893:x 4865:p 4847:/ 4840:+ 4825:2 4821:/ 4799:r 4784:, 4778:) 4766:( 4756:p 4751:= 4748:r 4718:. 4706:r 4703:= 4700:y 4696:, 4684:r 4681:= 4678:x 4664:) 4662:θ 4658:r 4656:( 4629:A 4612:) 4608:a 4600:b 4596:( 4590:+ 4586:a 4582:= 4578:r 4563:b 4555:a 4533:B 4530:A 4522:+ 4518:A 4515:O 4511:= 4507:r 4483:π 4404:c 4399:c 4392:p 4388:c 4382:π 4380:2 4354:p 4348:p 4311:. 4304:2 4300:b 4296:+ 4291:2 4287:a 4277:| 4273:c 4269:| 4264:c 4242:c 4239:= 4236:y 4233:b 4230:+ 4227:x 4224:a 4213:p 4207:x 4172:, 4169:0 4166:= 4163:p 4148:y 4145:+ 4133:x 4074:c 4070:b 4066:a 4064:( 4058:c 4054:b 4050:a 4044:0 4041:z 4037:0 4034:y 4030:0 4027:x 4025:( 4020:t 4016:z 4012:y 4008:x 3987:t 3984:c 3981:+ 3976:0 3972:z 3968:= 3961:z 3954:t 3951:b 3948:+ 3943:0 3939:y 3935:= 3928:y 3921:t 3918:a 3915:+ 3910:0 3906:x 3902:= 3895:x 3842:0 3839:= 3836:t 3814:2 3810:c 3806:t 3803:= 3798:1 3794:c 3790:, 3785:2 3781:b 3777:t 3774:= 3769:1 3765:b 3761:, 3756:2 3752:a 3748:t 3745:= 3740:1 3736:a 3715:) 3710:2 3706:c 3702:, 3697:2 3693:b 3689:, 3684:2 3680:a 3676:( 3656:) 3651:1 3647:c 3643:, 3638:1 3634:b 3630:, 3625:1 3621:a 3617:( 3597:0 3594:= 3589:2 3585:d 3578:z 3573:2 3569:c 3565:+ 3562:y 3557:2 3553:b 3549:+ 3546:x 3541:2 3537:a 3517:0 3514:= 3509:1 3505:d 3498:z 3493:1 3489:c 3485:+ 3482:y 3477:1 3473:b 3469:+ 3466:x 3461:1 3457:a 3428:a 3424:y 3420:+ 3417:) 3412:a 3408:x 3401:x 3398:( 3395:m 3392:= 3389:y 3369:) 3364:a 3360:x 3351:b 3347:x 3343:( 3339:/ 3335:) 3330:a 3326:y 3317:b 3313:y 3309:( 3306:= 3303:m 3281:b 3277:x 3268:a 3264:x 3243:) 3238:b 3234:y 3230:, 3225:b 3221:x 3217:( 3214:B 3194:) 3189:a 3185:y 3181:, 3176:a 3172:x 3168:( 3165:A 3153:. 3151:) 3149:x 3147:( 3145:f 3141:y 3132:x 3122:b 3108:m 3091:b 3088:+ 3085:x 3082:m 3079:= 3076:y 3044:. 3035:0 3031:x 3022:1 3018:x 3010:1 3006:y 3000:0 2996:x 2987:0 2983:y 2977:1 2973:x 2966:+ 2958:0 2954:x 2945:1 2941:x 2933:0 2929:y 2920:1 2916:y 2908:x 2905:= 2902:y 2880:0 2876:y 2872:+ 2864:0 2860:x 2851:1 2847:x 2839:0 2835:y 2826:1 2822:y 2814:) 2809:0 2805:x 2798:x 2795:( 2792:= 2789:y 2778:1 2775:x 2771:0 2768:x 2753:. 2750:) 2745:0 2741:x 2734:x 2731:( 2728:) 2723:0 2719:y 2710:1 2706:y 2702:( 2699:= 2696:) 2691:0 2687:x 2678:1 2674:x 2670:( 2667:) 2662:0 2658:y 2651:y 2648:( 2628:) 2623:1 2619:y 2615:, 2610:1 2606:x 2602:( 2597:1 2593:P 2572:) 2567:0 2563:y 2559:, 2554:0 2550:x 2546:( 2541:0 2537:P 2502:, 2499:0 2496:= 2493:c 2487:y 2484:b 2481:+ 2478:x 2475:a 2458:c 2452:c 2445:c 2437:b 2433:b 2429:a 2417:c 2413:b 2409:a 2395:, 2392:} 2389:c 2386:= 2383:y 2380:b 2377:+ 2374:x 2371:a 2365:) 2362:y 2359:, 2356:x 2353:( 2350:{ 2347:= 2344:L 2334:y 2330:x 2328:( 2312:L 2158:. 2145:, 2121:i 2117:i 2007:. 2005:c 2001:x 1997:b 1995:, 1993:c 1991:( 1989:d 1985:b 1983:, 1981:x 1979:( 1977:d 1973:a 1971:, 1969:c 1967:( 1965:d 1961:a 1959:, 1957:x 1955:( 1953:d 1949:c 1945:b 1941:a 1933:b 1929:a 1925:b 1923:, 1921:a 1919:( 1917:d 1903:k 1899:k 1887:n 1867:] 1859:n 1855:z 1842:2 1838:z 1830:1 1826:z 1820:1 1811:n 1807:y 1794:2 1790:y 1782:1 1778:y 1772:1 1763:n 1759:x 1746:2 1742:x 1734:1 1730:x 1724:1 1718:[ 1702:n 1698:z 1694:2 1691:z 1687:1 1684:z 1680:Z 1675:n 1671:y 1667:2 1664:y 1660:1 1657:y 1653:Y 1648:n 1644:x 1640:2 1637:x 1633:1 1630:x 1626:X 1622:n 1589:b 1585:a 1581:a 1577:b 1573:t 1571:( 1569:b 1565:t 1563:( 1561:a 1543:. 1539:} 1534:R 1527:t 1521:b 1518:t 1515:+ 1512:a 1508:) 1505:t 1499:1 1496:( 1492:{ 1488:= 1485:L 1475:b 1471:a 1467:L 1459:R 1445:n 1441:n 1437:n 1433:z 1429:y 1425:x 1200:e 1193:t 1186:v 327:) 323:( 105:) 101:( 40:. 20:)

Index

Straight line
Line (graphics)
Line
see caption
origin
Cartesian coordinate system
Geometry
Stereographic projection from the top of a sphere onto a plane beneath it
Projecting
sphere
plane
Outline
History
Timeline
Branches
Euclidean
Non-Euclidean
Elliptic
Spherical
Hyperbolic
Non-Archimedean geometry
Projective
Affine
Synthetic
Analytic
Algebraic
Arithmetic
Diophantine
Differential
Riemannian

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