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Ceva's theorem

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56: 38: 2612: 985: 1357: 1642: 1503: 462: 260: 2270: 2059: 769: 2476: 1773: 780: 1219: 1108: 2447: 1230: 2364: 1525: 1386: 345: 146: 2156: 1945: 614: 2130: 1934: 1869: 2607:{\displaystyle {\frac {\overline {BD}}{\overline {DC}}}={\frac {\lambda _{C}}{\lambda _{B}}}\quad {\text{and}}\quad {\frac {\overline {CE}}{\overline {EA}}}={\frac {\lambda _{A}}{\lambda _{C}}}.} 2685:)-face. Each of these points divides the face on which it lies into lobes. Given a cycle of pairs of lobes, the product of the ratios of the volumes of the lobes in each pair is 1. 2691:
gives the area of the triangle formed by three cevians in the case that they are not concurrent. Ceva's theorem can be obtained from it by setting the area equal to zero and solving.
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The theorem also has a well-known generalization to spherical and hyperbolic geometry, replacing the lengths in the ratios with their sines and hyperbolic sines, respectively.
980:{\displaystyle {\frac {\overline {BD}}{\overline {DC}}}={\frac {|\triangle BAD|-|\triangle BOD|}{|\triangle CAD|-|\triangle COD|}}={\frac {|\triangle ABO|}{|\triangle CAO|}}.} 1119: 1008: 1688: 562:
The first one is very elementary, using only basic properties of triangle areas. However, several cases have to be considered, depending on the position of the point
2375: 1352:{\displaystyle \left|{\frac {\overline {AF}}{\overline {FB}}}\cdot {\frac {\overline {BD}}{\overline {DC}}}\cdot {\frac {\overline {CE}}{\overline {EA}}}\right|=1,} 2293: 2663:
extends the conclusion of Ceva's theorem that the product of certain ratios is 1. Starting from a point in a simplex, a point is defined inductively on each
1637:{\displaystyle {\frac {\overline {BA}}{\overline {AF}}}\cdot {\frac {\overline {FO}}{\overline {OC}}}\cdot {\frac {\overline {CD}}{\overline {DB}}}=-1.} 1498:{\displaystyle {\frac {\overline {AB}}{\overline {BF}}}\cdot {\frac {\overline {FO}}{\overline {OC}}}\cdot {\frac {\overline {CE}}{\overline {EA}}}=-1} 457:{\displaystyle {\frac {\overline {AF}}{\overline {FB}}}\cdot {\frac {\overline {BD}}{\overline {DC}}}\cdot {\frac {\overline {CE}}{\overline {EA}}}=1,} 255:{\displaystyle {\frac {\overline {AF}}{\overline {FB}}}\cdot {\frac {\overline {BD}}{\overline {DC}}}\cdot {\frac {\overline {CE}}{\overline {EA}}}=1.} 308:, in the sense that it may be stated and proved without using the concepts of angles, areas, and lengths (except for the ratio of the lengths of two 2265:{\displaystyle {\overrightarrow {FO}}-\lambda _{C}{\overrightarrow {FC}}=\lambda _{A}{\overrightarrow {FA}}+\lambda _{B}{\overrightarrow {FB}}.} 2054:{\displaystyle {\overrightarrow {XO}}=\lambda _{A}{\overrightarrow {XA}}+\lambda _{B}{\overrightarrow {XB}}+\lambda _{C}{\overrightarrow {XC}},} 764:{\displaystyle {\frac {|\triangle BOD|}{|\triangle COD|}}={\frac {\overline {BD}}{\overline {DC}}}={\frac {|\triangle BAD|}{|\triangle CAD|}}.} 2782: 2630: 3120: 2698:
in the plane has been known since the early nineteenth century. The theorem has also been generalized to triangles on other surfaces of
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Experimentally finding the centroid of a triangle with different weights at the vertices: a practical application of Ceva's theorem
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To check the magnitude, note that the area of a triangle of a given height is proportional to its base. So
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includes definitions of cevian triangle, cevian nest, anticevian triangle, Ceva conjugate, and cevapoint
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is supposed to not belong to any line passing through two vertices of the triangle. This implies that
2740: 540: 1214:{\displaystyle {\frac {\overline {AF}}{\overline {FB}}}={\frac {|\triangle CAO|}{|\triangle BCO|}}.} 1103:{\displaystyle {\frac {\overline {CE}}{\overline {EA}}}={\frac {|\triangle BCO|}{|\triangle ABO|}},} 601:
is inside the triangle (upper diagram), or one is positive and the other two are negative, the case
3162: 2714: 2645: 1768:{\displaystyle {\frac {\overline {AF}}{\overline {FB}}}={\frac {\overline {AF'}}{\overline {F'B}}}} 582: 476: 321: 3173: 3041: 3006: 2971: 2932: 2897: 2699: 74: 2688: 2774: 2287:
are not collinear. It follows that the two members of the equation equal the zero vector, and
3145: 2778: 2719: 2649: 2442:{\displaystyle {\frac {\overline {AF}}{\overline {FB}}}={\frac {\lambda _{B}}{\lambda _{A}}},} 574: 100: 3076: 3033: 2998: 2963: 2924: 2889: 2766: 1803: 472: 2799: 2652:
can be assigned to the vertices such that each cevian intersects the opposite facet at its
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Landy, Steven (December 1988). "A Generalization of Ceva's Theorem to Higher Dimensions".
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Geometric relation between line segments from a triangle's vertices and their intersection
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Wernicke, Paul (November 1927). "The Theorems of Ceva and Menelaus and Their Extension".
2864: 3102: 2656:. Moreover, the intersection point of the cevians is the center of mass of the simplex. 2359:{\displaystyle \lambda _{A}{\overrightarrow {FA}}+\lambda _{B}{\overrightarrow {FB}}=0.} 2275:
The left-hand side of this equation is a vector that has the same direction as the line
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Several proofs of the theorem have been given. Two proofs are given in the following.
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Ceva's theorem results immediately by taking the product of the three last equations.
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where the left-hand-side fraction is the signed ratio of the lengths of the collinear
3194: 3045: 2975: 2767: 483: 3169:, an interactive dynamic geometry sketch using the gravity simulator of Cinderella. 3115: 3106: 2989:
Grünbaum, Branko; Shephard, G. C. (1995). "Ceva, Menelaus and the Area Principle".
2453: 2069: 1807: 1795: 578: 570: 317: 313: 309: 137: 3148: 3132: 2967: 55: 37: 3065:"Al-Mutaman ibn Hűd, 11the century king of Saragossa and brilliant mathematician" 2830: 2667:-face. This point is the foot of a cevian that goes from the vertex opposite the 3024:
Masal'tsev, L. A. (1994). "Incidence theorems in spaces of constant curvature".
577:, but is somehow more natural and not case dependent. Moreover, it works in any 544: 17: 597:
is positive since either all three of the ratios are positive, the case where
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in that their equations differ only in sign. By re-writing each in terms of
3081: 3064: 2800:"A Unified Proof of Ceva and Menelaus' Theorems Using Projective Geometry" 2735: 495: 82: 501:
Associated with the figures are several terms derived from Ceva's name:
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Ceva's theorem, case 2: the three lines are concurrent at a point
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Ceva's theorem, case 1: the three lines are concurrent at a point
36: 2637:-simplex as a ray from each vertex to a point on the opposite ( 2852:, pages 177–180, Dover Publishing Co., second revised edition. 2279:, and the right-hand side has the same direction as the line 1778:
But at most one point can cut a segment in a given ratio so
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Russell, John Wellesley (1905). "Ch. 1 §7 Ceva's Theorem".
2125:{\displaystyle \lambda _{A}\lambda _{B}\lambda _{C}\neq 0.} 2950:
Samet, Dov (May 2021). "An Extension of Ceva's Theorem to
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Conics Associated with a Cevian Nest, by Clark Kimberling
1929:{\displaystyle \lambda _{A}+\lambda _{B}+\lambda _{C}=1,} 479:. The converse is often included as part of the theorem. 271:
is taken to be positive or negative according to whether
2150:(see figures), the last equation may be rearranged into 605:
is outside the triangle (lower diagram shows one case).
528:); cevian nest, anticevian triangle, Ceva conjugate. ( 1864:{\displaystyle \lambda _{A},\lambda _{B},\lambda _{C}} 2648:). Then the cevians are concurrent if and only if a 2625:
The theorem can be generalized to higher-dimensional
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The theorem follows by dividing these two equations.
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in some fixed orientation of the line. For example,
1678:. Then by the theorem, the equation also holds for 2606: 2441: 2358: 2264: 2124: 2053: 1928: 1863: 1767: 1636: 1497: 1351: 1213: 1102: 979: 763: 456: 254: 3103:Derivations and applications of Ceva's Theorem 2283:. These lines have different directions since 2659:Another generalization to higher-dimensional 316:). It is therefore true for triangles in any 8: 3121:Glossary of Encyclopedia of Triangle Centers 1365:The theorem can also be proven easily using 2863:Hopkins, George Irving (1902). "Art. 986". 3080: 2593: 2583: 2577: 2544: 2538: 2529: 2519: 2513: 2480: 2478: 2428: 2418: 2412: 2379: 2377: 2335: 2329: 2307: 2301: 2295: 2244: 2238: 2216: 2210: 2188: 2182: 2160: 2158: 2110: 2100: 2090: 2084: 2033: 2027: 2005: 1999: 1977: 1971: 1949: 1947: 1911: 1898: 1885: 1879: 1855: 1842: 1829: 1823: 1725: 1692: 1690: 1650:The converse follows as a corollary. Let 1595: 1562: 1529: 1527: 1456: 1423: 1390: 1388: 1305: 1272: 1239: 1232: 1200: 1183: 1176: 1159: 1156: 1123: 1121: 1089: 1072: 1065: 1048: 1045: 1012: 1010: 966: 949: 942: 925: 922: 911: 894: 886: 869: 862: 845: 837: 820: 817: 784: 782: 750: 733: 726: 709: 706: 673: 662: 645: 638: 621: 618: 616: 415: 382: 349: 347: 289:is defined as having positive value when 216: 183: 150: 148: 2694:The analogue of the theorem for general 1224:Multiplying these three equations gives 2757: 7: 3112:Trigonometric Form of Ceva's Theorem 2824: 2822: 2820: 490:. But it was proven much earlier by 486:, who published it in his 1678 work 482:The theorem is often attributed to 1188: 1164: 1077: 1053: 990:(Replace the minus with a plus if 954: 930: 899: 874: 850: 825: 738: 714: 650: 626: 547:, the two theorems may be seen as 25: 2956:The American Mathematical Monthly 2917:The American Mathematical Monthly 2882:The American Mathematical Monthly 2807:Journal for Geometry and Graphics 3026:Journal of Mathematical Sciences 2850:Challenging Problems in Geometry 1658:so that the equation holds. Let 2848:and Charles T. Salkind (1996), 2769:Geometry: Our Cultural Heritage 2543: 2537: 539:The theorem is very similar to 304:Ceva's theorem is a theorem of 3138:Wolfram Demonstrations Project 2731:Menelaus's theorem - Knowledge 2075:For Ceva's theorem, the point 1201: 1184: 1177: 1160: 1090: 1073: 1066: 1049: 967: 950: 943: 926: 912: 895: 887: 870: 863: 846: 838: 821: 751: 734: 727: 710: 663: 646: 639: 622: 494:, an eleventh-century king of 1: 2968:10.1080/00029890.2021.1896292 2741:Stewart's theorem - Knowledge 1818:are the unique three numbers 1786:Using barycentric coordinates 114:), to meet opposite sides at 2568: 2555: 2504: 2491: 2403: 2390: 1759: 1741: 1716: 1703: 1619: 1606: 1586: 1573: 1553: 1540: 1480: 1467: 1447: 1434: 1414: 1401: 1329: 1316: 1296: 1283: 1263: 1250: 1147: 1134: 1036: 1023: 808: 795: 697: 684: 439: 426: 406: 393: 373: 360: 240: 227: 207: 194: 174: 161: 118:respectively. (The segments 107:(not on one of the sides of 3179:Encyclopedia of Mathematics 1802:, that belongs to the same 275:is to the left or right of 265:In other words, the length 3227: 524:is the cevian triangle of 138:signed lengths of segments 29: 3167:Dynamic Geometry Sketches 3063:Hogendijk, J. B. (1995). 2470:The same reasoning shows 1508:and from the transversal 998:are on opposite sides of 536:is pronounced chev'ian.) 492:Yusuf Al-Mu'taman ibn Hűd 3211:Euclidean plane geometry 3206:Theorems about triangles 2866:Inductive Plane Geometry 2633:. Define a cevian of an 331:is also true: If points 301:and negative otherwise. 2798:Benitez, Julio (2007). 2631:barycentric coordinates 1808:barycentric coordinates 1369:. From the transversal 593:First, the sign of the 571:barycentric coordinates 532:is pronounced Chay'va; 3082:10.1006/hmat.1995.1001 2869:. D.C. Heath & Co. 2608: 2443: 2360: 2266: 2126: 2055: 1930: 1865: 1769: 1682:. Comparing the two, 1654:be given on the lines 1638: 1499: 1353: 1215: 1104: 981: 765: 569:The second proof uses 458: 339:respectively so that 256: 70: 52: 2846:Alfred S. Posamentier 2765:Holme, Audun (2010). 2726:Circumcevian triangle 2609: 2444: 2361: 2267: 2127: 2056: 1931: 1866: 1770: 1639: 1500: 1354: 1216: 1105: 982: 766: 459: 257: 58: 40: 32:Ceva (disambiguation) 3069:Historia Mathematica 2991:Mathematics Magazine 2773:. Springer. p.  2736:Triangle - Knowledge 2477: 2376: 2294: 2157: 2083: 1946: 1878: 1822: 1689: 1526: 1387: 1231: 1120: 1009: 781: 615: 589:Using triangle areas 346: 147: 30:For other uses, see 3136:by Jay Warendorff, 2715:Projective geometry 1790:Given three points 1670:be the point where 509:are the cevians of 327:A slightly adapted 85:. Given a triangle 81:is a theorem about 3146:Weisstein, Eric W. 3038:10.1007/BF01249519 2835:. Clarendon Press. 2746:Cevian - Knowledge 2700:constant curvature 2604: 2439: 2356: 2262: 2122: 2051: 1926: 1861: 1765: 1634: 1495: 1367:Menelaus's theorem 1349: 1211: 1100: 977: 761: 454: 252: 103:to a common point 99:be drawn from the 75:Euclidean geometry 71: 53: 3097:Menelaus and Ceva 2784:978-3-642-14440-0 2720:Median (geometry) 2650:mass distribution 2599: 2572: 2571: 2558: 2541: 2535: 2508: 2507: 2494: 2434: 2407: 2406: 2393: 2369:It follows that 2348: 2320: 2257: 2229: 2201: 2173: 2138:the intersection 2134:If one takes for 2046: 2018: 1990: 1962: 1763: 1762: 1744: 1720: 1719: 1706: 1623: 1622: 1609: 1590: 1589: 1576: 1557: 1556: 1543: 1484: 1483: 1470: 1451: 1450: 1437: 1418: 1417: 1404: 1333: 1332: 1319: 1300: 1299: 1286: 1267: 1266: 1253: 1206: 1151: 1150: 1137: 1095: 1040: 1039: 1026: 972: 917: 812: 811: 798: 756: 701: 700: 687: 668: 541:Menelaus' theorem 443: 442: 429: 410: 409: 396: 377: 376: 363: 244: 243: 230: 211: 210: 197: 178: 177: 164: 16:(Redirected from 3218: 3187: 3159: 3158: 3149:"Ceva's Theorem" 3086: 3084: 3050: 3049: 3032:(4): 3201–3206. 3021: 3015: 3014: 2986: 2980: 2979: 2947: 2941: 2940: 2912: 2906: 2905: 2877: 2871: 2870: 2859: 2853: 2843: 2837: 2836: 2826: 2815: 2814: 2804: 2795: 2789: 2788: 2772: 2762: 2722:– an application 2684: 2677: 2670: 2666: 2643: 2636: 2613: 2611: 2610: 2605: 2600: 2598: 2597: 2588: 2587: 2578: 2573: 2567: 2559: 2554: 2546: 2545: 2542: 2539: 2536: 2534: 2533: 2524: 2523: 2514: 2509: 2503: 2495: 2490: 2482: 2481: 2466: 2465: 2460: 2459: 2448: 2446: 2445: 2440: 2435: 2433: 2432: 2423: 2422: 2413: 2408: 2402: 2394: 2389: 2381: 2380: 2365: 2363: 2362: 2357: 2349: 2344: 2336: 2334: 2333: 2321: 2316: 2308: 2306: 2305: 2286: 2282: 2278: 2271: 2269: 2268: 2263: 2258: 2253: 2245: 2243: 2242: 2230: 2225: 2217: 2215: 2214: 2202: 2197: 2189: 2187: 2186: 2174: 2169: 2161: 2149: 2145: 2141: 2137: 2131: 2129: 2128: 2123: 2115: 2114: 2105: 2104: 2095: 2094: 2078: 2067: 2064:for every point 2060: 2058: 2057: 2052: 2047: 2042: 2034: 2032: 2031: 2019: 2014: 2006: 2004: 2003: 1991: 1986: 1978: 1976: 1975: 1963: 1958: 1950: 1935: 1933: 1932: 1927: 1916: 1915: 1903: 1902: 1890: 1889: 1870: 1868: 1867: 1862: 1860: 1859: 1847: 1846: 1834: 1833: 1817: 1814:with respect of 1813: 1801: 1793: 1781: 1774: 1772: 1771: 1766: 1764: 1758: 1754: 1745: 1740: 1739: 1727: 1726: 1721: 1715: 1707: 1702: 1694: 1693: 1681: 1677: 1673: 1669: 1665: 1661: 1657: 1653: 1643: 1641: 1640: 1635: 1624: 1618: 1610: 1605: 1597: 1596: 1591: 1585: 1577: 1572: 1564: 1563: 1558: 1552: 1544: 1539: 1531: 1530: 1518: 1511: 1504: 1502: 1501: 1496: 1485: 1479: 1471: 1466: 1458: 1457: 1452: 1446: 1438: 1433: 1425: 1424: 1419: 1413: 1405: 1400: 1392: 1391: 1379: 1372: 1358: 1356: 1355: 1350: 1339: 1335: 1334: 1328: 1320: 1315: 1307: 1306: 1301: 1295: 1287: 1282: 1274: 1273: 1268: 1262: 1254: 1249: 1241: 1240: 1220: 1218: 1217: 1212: 1207: 1205: 1204: 1187: 1181: 1180: 1163: 1157: 1152: 1146: 1138: 1133: 1125: 1124: 1109: 1107: 1106: 1101: 1096: 1094: 1093: 1076: 1070: 1069: 1052: 1046: 1041: 1035: 1027: 1022: 1014: 1013: 1001: 997: 993: 986: 984: 983: 978: 973: 971: 970: 953: 947: 946: 929: 923: 918: 916: 915: 898: 890: 873: 867: 866: 849: 841: 824: 818: 813: 807: 799: 794: 786: 785: 770: 768: 767: 762: 757: 755: 754: 737: 731: 730: 713: 707: 702: 696: 688: 683: 675: 674: 669: 667: 666: 649: 643: 642: 625: 619: 604: 600: 565: 549:projective duals 527: 523: 512: 508: 488:De lineis rectis 470: 463: 461: 460: 455: 444: 438: 430: 425: 417: 416: 411: 405: 397: 392: 384: 383: 378: 372: 364: 359: 351: 350: 338: 334: 300: 296: 292: 288: 287: 283: 278: 274: 270: 269: 261: 259: 258: 253: 245: 239: 231: 226: 218: 217: 212: 206: 198: 193: 185: 184: 179: 173: 165: 160: 152: 151: 131: 130: 126: 122: 117: 113: 106: 98: 91: 69: 62: 51: 44: 21: 3226: 3225: 3221: 3220: 3219: 3217: 3216: 3215: 3201:Affine geometry 3191: 3190: 3172: 3144: 3143: 3093: 3062: 3059: 3057:Further reading 3054: 3053: 3023: 3022: 3018: 3003:10.2307/2690569 2988: 2987: 2983: 2949: 2948: 2944: 2929:10.2307/2300222 2914: 2913: 2909: 2894:10.2307/2322390 2888:(10): 936–939. 2879: 2878: 2874: 2862: 2860: 2856: 2844: 2840: 2828: 2827: 2818: 2802: 2797: 2796: 2792: 2785: 2764: 2763: 2759: 2754: 2711: 2689:Routh's theorem 2679: 2672: 2668: 2664: 2638: 2634: 2623: 2621:Generalizations 2589: 2579: 2560: 2547: 2525: 2515: 2496: 2483: 2475: 2474: 2463: 2462: 2457: 2456: 2424: 2414: 2395: 2382: 2374: 2373: 2337: 2325: 2309: 2297: 2292: 2291: 2284: 2280: 2276: 2246: 2234: 2218: 2206: 2190: 2178: 2162: 2155: 2154: 2147: 2143: 2139: 2135: 2106: 2096: 2086: 2081: 2080: 2076: 2065: 2035: 2023: 2007: 1995: 1979: 1967: 1951: 1944: 1943: 1907: 1894: 1881: 1876: 1875: 1851: 1838: 1825: 1820: 1819: 1815: 1811: 1799: 1791: 1788: 1779: 1747: 1746: 1732: 1728: 1708: 1695: 1687: 1686: 1679: 1675: 1671: 1667: 1663: 1659: 1655: 1651: 1611: 1598: 1578: 1565: 1545: 1532: 1524: 1523: 1513: 1509: 1472: 1459: 1439: 1426: 1406: 1393: 1385: 1384: 1374: 1370: 1321: 1308: 1288: 1275: 1255: 1242: 1238: 1234: 1229: 1228: 1182: 1158: 1139: 1126: 1118: 1117: 1071: 1047: 1028: 1015: 1007: 1006: 999: 995: 991: 948: 924: 868: 819: 800: 787: 779: 778: 732: 708: 689: 676: 644: 620: 613: 612: 602: 598: 591: 563: 557: 525: 518: 515:cevian triangle 510: 506: 475:, or all three 468: 431: 418: 398: 385: 365: 352: 344: 343: 336: 332: 306:affine geometry 298: 294: 290: 285: 281: 280: 276: 272: 267: 266: 232: 219: 199: 186: 166: 153: 145: 144: 136:.) Then, using 128: 124: 120: 119: 115: 108: 104: 96: 86: 64: 60: 46: 42: 35: 28: 23: 22: 18:Cevian triangle 15: 12: 11: 5: 3224: 3222: 3214: 3213: 3208: 3203: 3193: 3192: 3189: 3188: 3174:"Ceva theorem" 3170: 3160: 3141: 3133:Ceva's Theorem 3129: 3124: 3118: 3109: 3100: 3092: 3091:External links 3089: 3088: 3087: 3058: 3055: 3052: 3051: 3016: 2997:(4): 254–268. 2981: 2962:(5): 435–445. 2942: 2923:(9): 468–472. 2907: 2872: 2854: 2838: 2816: 2790: 2783: 2756: 2755: 2753: 2750: 2749: 2748: 2743: 2738: 2733: 2728: 2723: 2717: 2710: 2707: 2654:center of mass 2622: 2619: 2615: 2614: 2603: 2596: 2592: 2586: 2582: 2576: 2570: 2566: 2563: 2557: 2553: 2550: 2532: 2528: 2522: 2518: 2512: 2506: 2502: 2499: 2493: 2489: 2486: 2450: 2449: 2438: 2431: 2427: 2421: 2417: 2411: 2405: 2401: 2398: 2392: 2388: 2385: 2367: 2366: 2355: 2352: 2347: 2343: 2340: 2332: 2328: 2324: 2319: 2315: 2312: 2304: 2300: 2273: 2272: 2261: 2256: 2252: 2249: 2241: 2237: 2233: 2228: 2224: 2221: 2213: 2209: 2205: 2200: 2196: 2193: 2185: 2181: 2177: 2172: 2168: 2165: 2121: 2118: 2113: 2109: 2103: 2099: 2093: 2089: 2062: 2061: 2050: 2045: 2041: 2038: 2030: 2026: 2022: 2017: 2013: 2010: 2002: 1998: 1994: 1989: 1985: 1982: 1974: 1970: 1966: 1961: 1957: 1954: 1937: 1936: 1925: 1922: 1919: 1914: 1910: 1906: 1901: 1897: 1893: 1888: 1884: 1858: 1854: 1850: 1845: 1841: 1837: 1832: 1828: 1798:, and a point 1787: 1784: 1776: 1775: 1761: 1757: 1753: 1750: 1743: 1738: 1735: 1731: 1724: 1718: 1714: 1711: 1705: 1701: 1698: 1645: 1644: 1633: 1630: 1627: 1621: 1617: 1614: 1608: 1604: 1601: 1594: 1588: 1584: 1581: 1575: 1571: 1568: 1561: 1555: 1551: 1548: 1542: 1538: 1535: 1506: 1505: 1494: 1491: 1488: 1482: 1478: 1475: 1469: 1465: 1462: 1455: 1449: 1445: 1442: 1436: 1432: 1429: 1422: 1416: 1412: 1409: 1403: 1399: 1396: 1360: 1359: 1348: 1345: 1342: 1338: 1331: 1327: 1324: 1318: 1314: 1311: 1304: 1298: 1294: 1291: 1285: 1281: 1278: 1271: 1265: 1261: 1258: 1252: 1248: 1245: 1237: 1222: 1221: 1210: 1203: 1199: 1196: 1193: 1190: 1186: 1179: 1175: 1172: 1169: 1166: 1162: 1155: 1149: 1145: 1142: 1136: 1132: 1129: 1111: 1110: 1099: 1092: 1088: 1085: 1082: 1079: 1075: 1068: 1064: 1061: 1058: 1055: 1051: 1044: 1038: 1034: 1031: 1025: 1021: 1018: 1002:.) Similarly, 988: 987: 976: 969: 965: 962: 959: 956: 952: 945: 941: 938: 935: 932: 928: 921: 914: 910: 907: 904: 901: 897: 893: 889: 885: 882: 879: 876: 872: 865: 861: 858: 855: 852: 848: 844: 840: 836: 833: 830: 827: 823: 816: 810: 806: 803: 797: 793: 790: 772: 771: 760: 753: 749: 746: 743: 740: 736: 729: 725: 722: 719: 716: 712: 705: 699: 695: 692: 686: 682: 679: 672: 665: 661: 658: 655: 652: 648: 641: 637: 634: 631: 628: 624: 595:left-hand side 590: 587: 556: 553: 517:(the triangle 465: 464: 453: 450: 447: 441: 437: 434: 428: 424: 421: 414: 408: 404: 401: 395: 391: 388: 381: 375: 371: 368: 362: 358: 355: 335:are chosen on 263: 262: 251: 248: 242: 238: 235: 229: 225: 222: 215: 209: 205: 202: 196: 192: 189: 182: 176: 172: 169: 163: 159: 156: 79:Ceva's theorem 26: 24: 14: 13: 10: 9: 6: 4: 3: 2: 3223: 3212: 3209: 3207: 3204: 3202: 3199: 3198: 3196: 3185: 3181: 3180: 3175: 3171: 3168: 3164: 3161: 3156: 3155: 3150: 3147: 3142: 3139: 3135: 3134: 3130: 3128: 3125: 3122: 3119: 3117: 3113: 3110: 3108: 3104: 3101: 3098: 3095: 3094: 3090: 3083: 3078: 3074: 3070: 3066: 3061: 3060: 3056: 3047: 3043: 3039: 3035: 3031: 3027: 3020: 3017: 3012: 3008: 3004: 3000: 2996: 2992: 2985: 2982: 2977: 2973: 2969: 2965: 2961: 2957: 2954:-Simplices". 2953: 2946: 2943: 2938: 2934: 2930: 2926: 2922: 2918: 2911: 2908: 2903: 2899: 2895: 2891: 2887: 2883: 2876: 2873: 2868: 2867: 2858: 2855: 2851: 2847: 2842: 2839: 2834: 2833: 2832:Pure Geometry 2825: 2823: 2821: 2817: 2812: 2808: 2801: 2794: 2791: 2786: 2780: 2776: 2771: 2770: 2761: 2758: 2751: 2747: 2744: 2742: 2739: 2737: 2734: 2732: 2729: 2727: 2724: 2721: 2718: 2716: 2713: 2712: 2708: 2706: 2703: 2701: 2697: 2692: 2690: 2686: 2682: 2675: 2671:-face, in a ( 2662: 2657: 2655: 2651: 2647: 2641: 2632: 2628: 2620: 2618: 2601: 2594: 2590: 2584: 2580: 2574: 2564: 2561: 2551: 2548: 2530: 2526: 2520: 2516: 2510: 2500: 2497: 2487: 2484: 2473: 2472: 2471: 2468: 2455: 2454:line segments 2436: 2429: 2425: 2419: 2415: 2409: 2399: 2396: 2386: 2383: 2372: 2371: 2370: 2353: 2350: 2345: 2341: 2338: 2330: 2326: 2322: 2317: 2313: 2310: 2302: 2298: 2290: 2289: 2288: 2259: 2254: 2250: 2247: 2239: 2235: 2231: 2226: 2222: 2219: 2211: 2207: 2203: 2198: 2194: 2191: 2183: 2179: 2175: 2170: 2166: 2163: 2153: 2152: 2151: 2142:of the lines 2132: 2119: 2116: 2111: 2107: 2101: 2097: 2091: 2087: 2073: 2071: 2048: 2043: 2039: 2036: 2028: 2024: 2020: 2015: 2011: 2008: 2000: 1996: 1992: 1987: 1983: 1980: 1972: 1968: 1964: 1959: 1955: 1952: 1942: 1941: 1940: 1923: 1920: 1917: 1912: 1908: 1904: 1899: 1895: 1891: 1886: 1882: 1874: 1873: 1872: 1856: 1852: 1848: 1843: 1839: 1835: 1830: 1826: 1809: 1805: 1797: 1794:that are not 1785: 1783: 1755: 1751: 1748: 1736: 1733: 1729: 1722: 1712: 1709: 1699: 1696: 1685: 1684: 1683: 1648: 1631: 1628: 1625: 1615: 1612: 1602: 1599: 1592: 1582: 1579: 1569: 1566: 1559: 1549: 1546: 1536: 1533: 1522: 1521: 1520: 1517: 1492: 1489: 1486: 1476: 1473: 1463: 1460: 1453: 1443: 1440: 1430: 1427: 1420: 1410: 1407: 1397: 1394: 1383: 1382: 1381: 1378: 1368: 1363: 1362:as required. 1346: 1343: 1340: 1336: 1325: 1322: 1312: 1309: 1302: 1292: 1289: 1279: 1276: 1269: 1259: 1256: 1246: 1243: 1235: 1227: 1226: 1225: 1208: 1197: 1194: 1191: 1173: 1170: 1167: 1153: 1143: 1140: 1130: 1127: 1116: 1115: 1114: 1097: 1086: 1083: 1080: 1062: 1059: 1056: 1042: 1032: 1029: 1019: 1016: 1005: 1004: 1003: 974: 963: 960: 957: 939: 936: 933: 919: 908: 905: 902: 891: 883: 880: 877: 859: 856: 853: 842: 834: 831: 828: 814: 804: 801: 791: 788: 777: 776: 775: 758: 747: 744: 741: 723: 720: 717: 703: 693: 690: 680: 677: 670: 659: 656: 653: 635: 632: 629: 611: 610: 609: 606: 596: 588: 586: 584: 580: 576: 572: 567: 560: 554: 552: 550: 546: 542: 537: 535: 531: 522: 516: 504: 499: 497: 493: 489: 485: 484:Giovanni Ceva 480: 478: 474: 451: 448: 445: 435: 432: 422: 419: 412: 402: 399: 389: 386: 379: 369: 366: 356: 353: 342: 341: 340: 330: 325: 323: 319: 315: 311: 310:line segments 307: 302: 249: 246: 236: 233: 223: 220: 213: 203: 200: 190: 187: 180: 170: 167: 157: 154: 143: 142: 141: 139: 135: 132:are known as 112: 102: 95: 90: 84: 80: 76: 68: 57: 50: 39: 33: 19: 3177: 3152: 3131: 3116:cut-the-knot 3107:cut-the-knot 3099:at MathPages 3072: 3068: 3029: 3025: 3019: 2994: 2990: 2984: 2959: 2955: 2951: 2945: 2920: 2916: 2910: 2885: 2881: 2875: 2865: 2857: 2849: 2841: 2831: 2810: 2806: 2793: 2768: 2760: 2704: 2693: 2687: 2680: 2673: 2658: 2639: 2624: 2616: 2469: 2451: 2368: 2274: 2133: 2074: 2070:Affine space 2063: 1938: 1789: 1777: 1649: 1646: 1515: 1512:of triangle 1507: 1376: 1373:of triangle 1364: 1361: 1223: 1112: 989: 773: 607: 592: 579:affine plane 568: 561: 558: 545:cross-ratios 538: 533: 529: 520: 514: 500: 487: 481: 466: 326: 318:affine plane 303: 264: 110: 88: 78: 72: 66: 48: 2813:(1): 39–44. 774:Therefore, 505:(the lines 293:is between 3195:Categories 2752:References 1871:such that 1656:BC, AC, AB 507:AD, BE, CF 473:concurrent 469:AD, BE, CF 337:BC, AC, AB 97:AO, BO, CO 92:, let the 3184:EMS Press 3154:MathWorld 3046:123870381 2976:233413469 2661:simplexes 2627:simplexes 2591:λ 2581:λ 2569:¯ 2556:¯ 2527:λ 2517:λ 2505:¯ 2492:¯ 2426:λ 2416:λ 2404:¯ 2391:¯ 2346:→ 2327:λ 2318:→ 2299:λ 2255:→ 2236:λ 2227:→ 2208:λ 2199:→ 2180:λ 2176:− 2171:→ 2117:≠ 2108:λ 2098:λ 2088:λ 2044:→ 2025:λ 2016:→ 1997:λ 1988:→ 1969:λ 1960:→ 1909:λ 1896:λ 1883:λ 1853:λ 1840:λ 1827:λ 1796:collinear 1760:¯ 1742:¯ 1717:¯ 1704:¯ 1629:− 1620:¯ 1607:¯ 1593:⋅ 1587:¯ 1574:¯ 1560:⋅ 1554:¯ 1541:¯ 1490:− 1481:¯ 1468:¯ 1454:⋅ 1448:¯ 1435:¯ 1421:⋅ 1415:¯ 1402:¯ 1330:¯ 1317:¯ 1303:⋅ 1297:¯ 1284:¯ 1270:⋅ 1264:¯ 1251:¯ 1189:△ 1165:△ 1148:¯ 1135:¯ 1078:△ 1054:△ 1037:¯ 1024:¯ 955:△ 931:△ 900:△ 892:− 875:△ 851:△ 843:− 826:△ 809:¯ 796:¯ 739:△ 715:△ 698:¯ 685:¯ 651:△ 627:△ 581:over any 440:¯ 427:¯ 413:⋅ 407:¯ 394:¯ 380:⋅ 374:¯ 361:¯ 320:over any 314:collinear 312:that are 241:¯ 228:¯ 214:⋅ 208:¯ 195:¯ 181:⋅ 175:¯ 162:¯ 83:triangles 3075:: 1–18. 2861:Follows 2709:See also 2696:polygons 2644:)-face ( 1752:′ 1737:′ 1680:D, E, F' 1674:crosses 1666:and let 1662:meet at 496:Zaragoza 477:parallel 329:converse 101:vertices 63:outside 3186:, 2001 3011:2690569 2937:2300222 2902:2322390 2285:A, B, C 1816:A, B, C 1792:A, B, C 1652:D, E, F 575:vectors 333:D, E, F 134:cevians 116:D, E, F 45:inside 3044:  3009:  2974:  2935:  2900:  2781:  2629:using 1806:, the 1780:F = F’ 1660:AD, BE 555:Proofs 534:cevian 503:cevian 3042:S2CID 3007:JSTOR 2972:S2CID 2933:JSTOR 2898:JSTOR 2803:(PDF) 2646:facet 1804:plane 583:field 467:then 322:field 94:lines 2779:ISBN 2461:and 2146:and 1939:and 1113:and 994:and 573:and 530:Ceva 471:are 297:and 3165:at 3114:at 3105:at 3077:doi 3034:doi 2999:doi 2964:doi 2960:128 2925:doi 2890:doi 2775:210 2683:+ 1 2676:+ 1 2642:– 1 2540:and 2072:). 1810:of 1516:BCF 1510:AOD 1377:ACF 1371:BOE 566:. 521:DEF 513:), 111:ABC 89:ABC 73:In 67:ABC 49:ABC 3197:: 3182:, 3176:, 3151:. 3073:22 3071:. 3067:. 3040:. 3030:72 3028:. 3005:. 2995:68 2993:. 2970:. 2958:. 2931:. 2921:34 2919:. 2896:. 2886:95 2884:. 2819:^ 2811:11 2809:. 2805:. 2777:. 2702:. 2467:. 2464:FB 2458:AF 2354:0. 2281:AB 2277:CF 2148:OC 2144:AB 2120:0. 1782:. 1676:AB 1672:CO 1668:F' 1632:1. 1519:, 1380:, 1000:BC 585:. 551:. 498:. 324:. 286:FB 284:/ 282:AF 268:XY 250:1. 140:, 129:CF 127:, 125:BE 123:, 121:AD 77:, 3157:. 3140:. 3085:. 3079:: 3048:. 3036:: 3013:. 3001:: 2978:. 2966:: 2952:n 2939:. 2927:: 2904:. 2892:: 2787:. 2681:k 2674:k 2669:k 2665:k 2640:n 2635:n 2602:. 2595:C 2585:A 2575:= 2565:A 2562:E 2552:E 2549:C 2531:B 2521:C 2511:= 2501:C 2498:D 2488:D 2485:B 2437:, 2430:A 2420:B 2410:= 2400:B 2397:F 2387:F 2384:A 2351:= 2342:B 2339:F 2331:B 2323:+ 2314:A 2311:F 2303:A 2260:. 2251:B 2248:F 2240:B 2232:+ 2223:A 2220:F 2212:A 2204:= 2195:C 2192:F 2184:C 2167:O 2164:F 2140:F 2136:X 2112:C 2102:B 2092:A 2077:O 2066:X 2049:, 2040:C 2037:X 2029:C 2021:+ 2012:B 2009:X 2001:B 1993:+ 1984:A 1981:X 1973:A 1965:= 1956:O 1953:X 1924:, 1921:1 1918:= 1913:C 1905:+ 1900:B 1892:+ 1887:A 1857:C 1849:, 1844:B 1836:, 1831:A 1812:O 1800:O 1756:B 1749:F 1734:F 1730:A 1723:= 1713:B 1710:F 1700:F 1697:A 1664:O 1626:= 1616:B 1613:D 1603:D 1600:C 1583:C 1580:O 1570:O 1567:F 1550:F 1547:A 1537:A 1534:B 1514:△ 1493:1 1487:= 1477:A 1474:E 1464:E 1461:C 1444:C 1441:O 1431:O 1428:F 1411:F 1408:B 1398:B 1395:A 1375:△ 1347:, 1344:1 1341:= 1337:| 1326:A 1323:E 1313:E 1310:C 1293:C 1290:D 1280:D 1277:B 1260:B 1257:F 1247:F 1244:A 1236:| 1209:. 1202:| 1198:O 1195:C 1192:B 1185:| 1178:| 1174:O 1171:A 1168:C 1161:| 1154:= 1144:B 1141:F 1131:F 1128:A 1098:, 1091:| 1087:O 1084:B 1081:A 1074:| 1067:| 1063:O 1060:C 1057:B 1050:| 1043:= 1033:A 1030:E 1020:E 1017:C 996:O 992:A 975:. 968:| 964:O 961:A 958:C 951:| 944:| 940:O 937:B 934:A 927:| 920:= 913:| 909:D 906:O 903:C 896:| 888:| 884:D 881:A 878:C 871:| 864:| 860:D 857:O 854:B 847:| 839:| 835:D 832:A 829:B 822:| 815:= 805:C 802:D 792:D 789:B 759:. 752:| 748:D 745:A 742:C 735:| 728:| 724:D 721:A 718:B 711:| 704:= 694:C 691:D 681:D 678:B 671:= 664:| 660:D 657:O 654:C 647:| 640:| 636:D 633:O 630:B 623:| 603:O 599:O 564:O 526:O 519:△ 511:O 452:, 449:1 446:= 436:A 433:E 423:E 420:C 403:C 400:D 390:D 387:B 370:B 367:F 357:F 354:A 299:B 295:A 291:F 277:Y 273:X 247:= 237:A 234:E 224:E 221:C 204:C 201:D 191:D 188:B 171:B 168:F 158:F 155:A 109:△ 105:O 87:△ 65:△ 61:O 47:△ 43:O 34:. 20:)

Index

Cevian triangle
Ceva (disambiguation)


Euclidean geometry
triangles
lines
vertices
cevians
signed lengths of segments
affine geometry
line segments
collinear
affine plane
field
converse
concurrent
parallel
Giovanni Ceva
Yusuf Al-Mu'taman ibn Hűd
Zaragoza
cevian
Menelaus' theorem
cross-ratios
projective duals
barycentric coordinates
vectors
affine plane
field
left-hand side

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