X427

COMPLEMENT OF X22

X427 is the complement of X22.
< A B C >: Reference Triangle △ABC < M_a M_b M_c >: Medial Triangle △M_a M_b M_c [ A B ]: Sideline AB (Base c = 1) [ B C ]: Sideline BC (Side a) [ C A ]: Sideline CA (Side b) { 2, 22 }: Euler Line { 2, 3 }: Euler Line { 11, 33 }: Central Line L(11, 33) { 12, 34 }: Central Line L(12, 34) { 6, 66 }: Central Line L(6, 66) { 51, 125 }: Central Line L(51, 125) A = Vertex A (0.0000, 0.0000) B = Vertex B (1.0000, 0.0000) C = Vertex C (0.6122, 0.5999) M_a = Midpoint M_a of BC (0.8061, 0.2999) M_b = Midpoint M_b of CA (0.3061, 0.2999) M_c = Midpoint M_c of AB (0.5000, 0.0000) X_2 = CENTROID (0.5374, 0.2000) X_22 = EXETER POINT (0.4143, -0.1221) X_3 = CIRCUMCENTER (0.5000, 0.1021) X_11 = FEUERBACH POINT (0.7347, 0.0667) X_33 = PERSPECTOR OF THE ORTHIC AND INTANGENTS TRIANGLES (0.6019, 0.3546) X_12 = {X(1),X(5)}-HARMONIC CONJUGATE OF X(11) (0.5641, 0.2407) X_34 = -BETH CONJUGATE OF X(4) (0.6332, 0.4792) X_6 = SYMMEDIAN POINT (LEMOINE POINT, GREBE POINT) (0.6000, 0.2672) X_66 = ISOGONAL CONJUGATE OF X(22) (0.5912, 1.0593) X_51 = CENTROID OF ORTHIC TRIANGLE (0.6093, 0.3186) X_125 = CENTER OF JERABEK HYPERBOLA (0.6803, 0.0260) X_427 = COMPLEMENT OF X(22) (0.5990, 0.3610) A B C Ma Mb Mc X2 X22 X3 X11 X33 X12 X34 X6 X66 X51 X125 X427 (a, b, c) = (5, 6, 7) | AB = 1

X427 (COMPLEMENT OF X22) constructed on acute reference triangle \((a, b, c) = (5, 6, 7)\) with unit baseline AB = \(1\).

Constructed Elements

Trilinears: \(\sec A + \cos(B - C)\)
Barycentrics: \(\tan A + \tan \omega : :\)
Search Value (6, 9, 13): \(16.125778007218\)
▸ Alternate Coordinates1 form
  • Barycentrics: \((a^{2} + b^{2} - c^{2}) \cdot (a^{2} - b^{2} + c^{2}) \cdot (b^{2} + c^{2}) : :\)

▸ Linear Combinations1 combination
  • X427 = \(3\) X2 + X7391, \(9\) X2 - X20062, X2 + \(3\) X31105, \(3\) X2 - \(5\) X31236, \(5\) X2 - \(3\) X47596, \(3\) X4 - X35480, \(3\) X4 + X35481, \(3\) X5 - \(4\) X13413, and many others

X427 lies on the cubics K517, K533, K539, K823, K836.

▸ Incident Central Lines627 lines

{1, 5090}, {2, 3}, {6, 66}, {8, 11396}, {9, 21015}, {10, 1829}, {11, 33}, {12, 34}, {19, 3925}, {32, 47298}, {39, 12143}, {51, 125}, {52, 6746}, {53, 232}, {54, 31804}, {55, 11393}, {56, 11392}, {57, 1892}, {64, 14542}, {68, 36747}, {69, 12167}, {76, 8890}, {83, 11380}, {92, 2969}, {98, 275}, {107, 29011}, {110, 39884}, {112, 251}, {113, 12133}, {114, 136}, {115, 1196}, {116, 5185}, {119, 12138}, {120, 5521}, {122, 46831}, {126, 5139}, {127, 13166}, {135, 31842}, {137, 23319}, {141, 1843}, {143, 13561}, {154, 31383}, {155, 23307}, {182, 37649}, {183, 317}, {184, 1503}, {185, 3574}, {193, 8892}, {211, 27370}, {214, 12137}, {216, 26905}, {225, 26481}, {226, 1876}, {230, 571}, {238, 14975}, {242, 52412}, {262, 2052}, {264, 305}, {265, 15472}, {273, 7179}, {278, 1390}, {281, 1851}, {286, 37664}, {316, 33651}, {318, 3705}, {323, 3410}, {324, 2967}, {340, 37671}, {343, 511}, {371, 8280}, {372, 8281}, {373, 44079}, {385, 27377}, {388, 1398}, {389, 20299}, {393, 7736}, {394, 1352}, {395, 8739}, {396, 8740}, {459, 14484}, {485, 3093}, {486, 3092}, {487, 23309}, {488, 23310}, {495, 1870}, {496, 6198}, {497, 7071}, {498, 11398}, {499, 11399}, {515, 51707}, {524, 8541}, {542, 34986}, {578, 6146}, {590, 5412}, {597, 37875}, {608, 34261}, {615, 5413}, {618, 12142}, {619, 12141}, {625, 5140}, {629, 22482}, {630, 22481}, {641, 12148}, {642, 12147}, {648, 41624}, {748, 2212}, {750, 1395}, {804, 47230}, {899, 40976}, {908, 27409}, {930, 3563}, {940, 44105}, {946, 1902}, {958, 11391}, {973, 49108}, {1007, 19583}, {1031, 3329}, {1039, 1722}, {1086, 24163}, {1105, 14860}, {1125, 11363}, {1147, 12134}, {1172, 33854}, {1180, 5523}, {1181, 14216}, {1184, 3767}, {1194, 5254}, {1204, 6696}, {1209, 10625}, {1213, 44103}, {1217, 18855}, {1235, 3933}, {1241, 9230}, {1249, 37665}, {1291, 40118}, {1297, 20626}, {1329, 1828}, {1350, 43653}, {1351, 6515}, {1353, 1994}, {1369, 14929}, {1376, 11383}, {1401, 46152}, {1426, 15844}, {1447, 7282}, {1452, 24914}, {1474, 17398}, {1495, 10192}, {1506, 3199}, {1511, 12140}, {1568, 15030}, {1576, 39086}, {1611, 13881}, {1614, 16659}, {1627, 10312}, {1629, 14165}, {1698, 7713}, {1737, 1905}, {1753, 15908}, {1785, 24239}, {1799, 7750}, {1824, 1848}, {1826, 1841}, {1827, 21239}, {1838, 1867}, {1842, 30768}, {1865, 37661}, {1878, 3814}, {1890, 2355}, {1891, 25466}, {1897, 29840}, {1900, 25639}, {1916, 37892}, {1953, 21911}, {1968, 7745}, {1973, 29647}, {1974, 3589}, {1975, 34254}, {1986, 10264}, {1990, 9300}, {1992, 11405}, {1993, 3564}, {2023, 14715}, {2056, 11646}, {2183, 21912}, {2207, 2548}, {2211, 20965}, {2356, 3720}, {2453, 47177}, {2482, 12132}, {2486, 47232}, {2493, 34981}, {2501, 10278}, {2549, 15880}, {2550, 11406}, {2881, 47205}, {2883, 11381}, {2892, 32251}, {2904, 43588}, {2905, 17000}, {2971, 34336}, {2974, 34338}, {2979, 6403}, {3006, 41013}, {3011, 40950}, {3051, 20021}, {3054, 10985}, {3055, 14806}, {3060, 3580}, {3068, 5410}, {3069, 5411}, {3070, 11474}, {3071, 11473}, {3087, 7735}, {3096, 11386}, {3108, 41366}, {3167, 18440}, {3168, 51358}, {3172, 8879}, {3186, 3314}, {3192, 37662}, {3203, 27366}, {3258, 42426}, {3266, 44142}, {3291, 40326}, {3527, 45010}, {3567, 23294}, {3616, 7718}, {3618, 19118}, {3647, 16114}, {3703, 20883}, {3740, 41611}, {3757, 5174}, {3763, 7716}, {3796, 46264}, {3818, 9306}, {3819, 24206}, {3820, 29679}, {4383, 44086}, {4994, 8883}, {5012, 14389}, {5044, 41609}, {5081, 7081}, {5095, 8584}, {5097, 11225}, {5146, 29873}, {5155, 5268}, {5190, 5513}, {5203, 8770}, {5207, 37894}, {5249, 25365}, {5272, 7741}, {5275, 50036}, {5297, 10592}, {5304, 19041}, {5305, 5359}, {5306, 6103}, {5310, 6284}, {5318, 11476}, {5321, 11475}, {5322, 7354}, {5345, 10483}, {5422, 18583}, {5432, 52427}, {5446, 5449}, {5475, 9515}, {5490, 26373}, {5491, 26374}, {5552, 11400}, {5590, 11389}, {5591, 11388}, {5596, 19125}, {5599, 11384}, {5600, 11385}, {5640, 26913}, {5654, 18451}, {5690, 41722}, {5718, 44113}, {5743, 44092}, {5800, 44094}, {5889, 31802}, {5891, 51392}, {5913, 50718}, {5921, 15431}, {5943, 19130}, {5946, 52000}, {5966, 30248}, {5972, 16165}, {5996, 14618}, {6000, 18388}, {6033, 41253}, {6090, 14826}, {6108, 31687}, {6109, 31688}, {6114, 6117}, {6115, 6116}, {6152, 21230}, {6212, 16033}, {6213, 16027}, {6260, 12136}, {6288, 37495}, {6291, 23311}, {6292, 12144}, {6331, 8842}, {6340, 14248}, {6406, 23312}, {6467, 15583}, {6524, 10002}, {6525, 17830}, {6560, 18290}, {6561, 18289}, {6564, 8854}, {6565, 8855}, {6593, 32239}, {6697, 9969}, {6699, 15473}, {6759, 16655}, {6776, 11402}, {7009, 17923}, {7085, 50861}, {7292, 10593}, {7592, 11457}, {7603, 33842}, {7608, 39284}, {7649, 44316}, {7687, 32743}, {7699, 11455}, {7717, 18230}, {7722, 11804}, {7752, 47846}, {7753, 14581}, {7762, 8878}, {7774, 9308}, {7776, 40123}, {7778, 41762}, {7788, 44134}, {7789, 30747}, {7792, 36794}, {7840, 38294}, {8222, 11394}, {8223, 11395}, {8263, 11188}, {8428, 34866}, {8537, 41628}, {8550, 13366}, {8680, 25343}, {8753, 42008}, {8792, 41513}, {8796, 14494}, {8877, 10415}, {8968, 48467}, {8981, 10880}, {9134, 47236}, {9148, 17994}, {9157, 10735}, {9483, 42396}, {9544, 46818}, {9605, 41361}, {9732, 11091}, {9733, 11090}, {9744, 11547}, {9752, 35710}, {9766, 45921}, {9777, 11433}, {9781, 26917}, {9786, 26937}, {9792, 26954}, {9820, 10539}, {9833, 19357}, {9993, 43462}, {10110, 32767}, {10189, 41357}, {10190, 47627}, {10263, 34826}, {10282, 13419}, {10327, 17757}, {10516, 17811}, {10523, 15666}, {10527, 11401}, {10547, 16277}, {10550, 51862}, {10559, 51405}, {10576, 35764}, {10577, 35765}, {10601, 14561}, {10632, 42124}, {10633, 42121}, {10641, 23302}, {10642, 23303}, {10733, 32227}, {10881, 13966}, {10982, 39571}, {11174, 17907}, {11197, 44131}, {11206, 26864}, {11216, 47277}, {11408, 11488}, {11409, 11489}, {11411, 12160}, {11412, 33523}, {11424, 12241}, {11425, 19467}, {11430, 18400}, {11432, 18916}, {11435, 26957}, {11436, 26956}, {11438, 23329}, {11470, 15004}, {11472, 32123}, {11566, 40685}, {11572, 21659}, {11808, 14076}, {12022, 15033}, {12038, 45286}, {12058, 37511}, {12079, 35908}, {12139, 12864}, {12146, 13089}, {12161, 32140}, {12162, 18488}, {12165, 12317}, {12166, 12318}, {12168, 12319}, {12169, 12320}, {12170, 12321}, {12171, 12322}, {12172, 12323}, {12174, 12324}, {12175, 12325}, {12242, 14864}, {12295, 15432}, {12298, 45861}, {12299, 45860}, {12300, 20424}, {12618, 21062}, {12827, 14984}, {13007, 13025}, {13008, 13026}, {13051, 23313}, {13052, 23314}, {13148, 16003}, {13171, 13203}, {13292, 25738}, {13352, 18474}, {13367, 34782}, {13394, 29012}, {13403, 18383}, {13409, 23635}, {13428, 49029}, {13439, 49028}, {13562, 20806}, {13668, 13701}, {13788, 13821}, {13851, 23324}, {13857, 47354}, {14111, 35887}, {14156, 43586}, {14157, 16658}, {14376, 17407}, {14458, 43530}, {14492, 16080}, {14516, 34148}, {14583, 43090}, {14593, 40801}, {14627, 46443}, {14644, 43391}, {14767, 51412}, {14852, 44413}, {14918, 38429}, {14983, 45020}, {15038, 45967}, {15060, 51391}, {15066, 18358}, {15069, 37672}, {15116, 32246}, {15118, 41616}, {15152, 16252}, {15448, 44082}, {15449, 16102}, {15463, 32423}, {15484, 41370}, {15487, 46835}, {15523, 17442}, {15543, 15552}, {15544, 35605}, {15589, 32001}, {15819, 22480}, {16030, 19174}, {16188, 16221}, {16228, 47802}, {16229, 34964}, {16231, 39508}, {16276, 32819}, {16580, 40959}, {16607, 18636}, {16657, 18390}, {17451, 21717}, {17747, 24054}, {17810, 26958}, {17949, 32449}, {18287, 41925}, {18344, 21260}, {18356, 32358}, {18424, 24855}, {18475, 44407}, {18809, 46436}, {18853, 18854}, {18951, 37493}, {19119, 20079}, {19128, 38110}, {19347, 34780}, {19366, 26955}, {19404, 19420}, {19405, 19421}, {19446, 23298}, {19447, 23299}, {19459, 36851}, {19568, 47730}, {19724, 19755}, {19725, 19754}, {19784, 51686}, {19799, 19839}, {20185, 40120}, {20192, 45311}, {20306, 42448}, {20376, 52008}, {21072, 29016}, {21318, 41007}, {21637, 34774}, {21639, 23326}, {21663, 23328}, {21969, 41586}, {22240, 42459}, {22352, 44882}, {22483, 22966}, {22497, 22555}, {22750, 43614}, {22970, 23308}, {24321, 24686}, {26359, 26371}, {26360, 26372}, {26361, 26375}, {26362, 26376}, {26363, 26377}, {26364, 26378}, {26866, 26929}, {26867, 26939}, {26868, 26945}, {26892, 26932}, {26893, 26942}, {26894, 26950}, {26919, 26951}, {29667, 31419}, {30749, 40325}, {30786, 40413}, {31125, 41676}, {31127, 35360}, {31131, 44428}, {31406, 39575}, {31655, 48317}, {31670, 33586}, {31867, 35717}, {32000, 37668}, {32002, 37688}, {32046, 52432}, {32062, 51403}, {32085, 40425}, {32136, 45732}, {32184, 52003}, {32223, 48895}, {32240, 32255}, {32269, 48901}, {32332, 32391}, {32333, 32346}, {32337, 32341}, {32911, 44097}, {33547, 46686}, {34380, 45794}, {34417, 47296}, {34751, 44439}, {34781, 43841}, {34945, 41363}, {35540, 45211}, {35603, 36753}, {35718, 35729}, {35719, 35720}, {35723, 39565}, {35895, 35896}, {35971, 40377}, {36898, 38427}, {37472, 43595}, {37478, 44201}, {37650, 44100}, {37775, 42135}, {37776, 42138}, {38253, 43951}, {38396, 39879}, {38872, 44529}, {38970, 38975}, {39071, 47200}, {39511, 39533}, {39512, 51513}, {39532, 44432}, {39534, 48182}, {39662, 43448}, {39803, 39813}, {39832, 39842}, {39998, 44146}, {40149, 45964}, {40684, 44145}, {41171, 43574}, {41482, 51033}, {41603, 50649}, {41673, 41714}, {42353, 46832}, {42873, 51939}, {43817, 43823}, {44091, 51126}, {44426, 44429}, {45400, 45472}, {45401, 45473}, {45689, 47206}, {46147, 46151}, {46242, 46288}, {46261, 51425}, {47105, 51343}, {47392, 51385}

▸ Functional Relations59 relations
  • X427 = midpoint of Xi and Xj for these {i,j}: {2, 31133}, {3, 31723}, {4, 378}, {22, 7391}, {112, 11605}, {184, 11550}, {1993, 11442}, {13352, 18474}, {15463, 44795}, {18570, 44288}, {24321, 24686}, {35480, 35481}

  • X427 = reflection of Xi in Xj for these {i,j}: {1, 51718}, {3, 52262}, {5, 39504}, {6, 51744}, {22, 6676}, {184, 23292}, {235, 45179}, {343, 21243}, {1843, 51994}, {7502, 140}, {12083, 16618}, {15760, 5}, {16102, 15449}, {16165, 5972}, {16387, 5159}, {16789, 141}, {18570, 44236}, {19127, 3589}, {25337, 3628}, {34177, 6697}, {37478, 44201}, {37969, 468}, {44210, 2}, {44218, 44287}, {44239, 3}, {44249, 18570}, {44259, 16238}, {44260, 6677}, {44261, 549}, {44262, 547}, {44263, 546}, {44285, 44218}, {46029, 13413}, {51692, 1125}

  • X427 = isogonal conjugate of X1176

  • X427 = isotomic conjugate of X1799

  • X427 = complement of X22

  • X427 = anticomplement of X6676

  • X427 = circumcircle-inverse of X21284

  • X427 = nine-point-circle-inverse of X468

  • X427 = orthocentroidal-circle-inverse of X25

  • X427 = polar-circle-inverse of X23

  • X427 = orthoptic-circle-of-the-Steiner-inellipse inverse of X186

  • X427 = 1st-Droz-Farney-circle-inverse of X45171

  • X427 = orthosymmedial-circle-inverse of X1112

  • X427 = polar conjugate of X83

  • X427 = antitomic image of X16102

  • X427 = complement of the isogonal conjugate of X66

  • X427 = complement of the isotomic conjugate of X18018

  • X427 = isotomic conjugate of the complement of X8878

  • X427 = isotomic conjugate of the isogonal conjugate of X1843

  • X427 = isogonal conjugate of the isotomic conjugate of X1235

  • X427 = isotomic conjugate of the polar conjugate of X27376

  • X427 = polar conjugate of the isotomic conjugate of X141

  • X427 = polar conjugate of the isogonal conjugate of X39

  • X427 = medial-isogonal conjugate of X206

  • X427 = orthic-isogonal conjugate of X1843

  • X427 = Xi-complementary conjugate of Xj for these (i,j): {1, 206}, {2, 21247}, {6, 16582}, {31, 40938}, {57, 17068}, {66, 10}, {1289, 8062}, {2156, 2}, {2353, 37}, {13854, 226}, {14376, 18589}, {15388, 16599}, {16277, 1215}, {18018, 2887}, {40146, 16584}, {40421, 21235}, {43678, 20305}, {44766, 4369}, {46244, 626}

  • X427 = Xi-Ceva conjugate of Xj for these (i,j): {2, 40938}, {4, 1843}, {112, 523}, {264, 1235}, {1235, 141}, {6331, 2501}, {8791, 468}, {8889, 8893}, {16747, 20883}, {17171, 17442}, {27376, 41584}, {34129, 16318}, {46151, 826}

  • X427 = Xi-cross conjugate of Xj for these (i,j): {39, 141}, {141, 47730}, {826, 46151}, {1843, 27376}, {2530, 46152}, {3005, 35325}, {21016, 20883}, {23642, 76}, {23666, 75}, {42442, 6}, {46026, 4}, {46654, 31067}

  • X427 = Xi-isoconjugate of Xj for these (i,j): {1, 1176}, {3, 82}, {6, 34055}, {19, 28724}, {31, 1799}, {48, 83}, {63, 251}, {69, 46289}, {71, 52376}, {75, 10547}, {163, 4580}, {184, 3112}, {228, 52394}, {248, 3405}, {255, 32085}, {293, 51862}, {304, 46288}, {308, 9247}, {525, 34072}, {647, 4599}, {656, 827}, {810, 4577}, {822, 42396}, {905, 4628}, {906, 10566}, {1331, 18108}, {1437, 18082}, {1760, 46765}, {1790, 18098}, {2169, 17500}, {2172, 40404}, {2193, 18097}, {3049, 4593}, {4020, 52395}, {4574, 39179}, {4592, 18105}, {4630, 14208}, {10317, 37221}, {14575, 18833}, {18070, 32661}, {19611, 51508}, {22384, 36081}, {46104, 52430}

  • X427 = Xi-Dao conjugate of Xj for these (i,j): {2, 1799}, {2, 40938}, {3, 141}, {3, 1176}, {6, 28724}, {9, 34055}, {22, 427}, {25, 8793}, {39, 69}, {63, 40585}, {82, 36103}, {83, 1249}, {115, 4580}, {132, 51862}, {184, 34452}, {206, 10547}, {251, 3162}, {339, 3267}, {525, 15449}, {647, 3124}, {827, 40596}, {1194, 45201}, {1843, 15270}, {3405, 39039}, {3589, 7767}, {3933, 6665}, {3934, 22062}, {4577, 39062}, {4599, 39052}, {5139, 18105}, {5190, 10566}, {5521, 18108}, {6523, 32085}, {7664, 37804}, {8673, 47413}, {14363, 17500}, {18097, 47345}, {20775, 52042}, {21458, 50938}, {22105, 48317}, {23093, 44312}

  • X427 = cevapoint of Xi and Xj for these (i,j): {2, 8878}, {25, 8792}, {39, 1843}, {115, 2514}, {3005, 39691}, {28666, 46026}

  • X427 = crosspoint of Xi and Xj for these (i,j): {2, 18018}, {4, 264}, {16747, 17171}

  • X427 = crosssum of Xi and Xj for these (i,j): {3, 184}, {6, 206}, {25, 51509}, {251, 51508}

  • X427 = trilinear pole of line {826, 21108}

  • X427 = crossdifference of every pair of points on line {647, 8673}

  • X427 = X2-line conjugate of X44894

  • X427 = X4-Hirst inverse of X420

  • X427 = X55 of orthic triangle if ABC is acute

  • X427 = exsimilicenter of nine-point circle and incircle of orthic triangle if ABC is acute; the insimilicenter is X235

  • X427 = intersection of tangents to nine-point circle at PU(4)

  • X427 = pole of orthic axis wrt the nine-point circle

  • X427 = pole wrt polar circle of trilinear polar of X83 (line X23X385)

  • X427 = X48-isoconjugate (polar conjugate) of X83

  • X427 = inverse-in-polar-circle of X23

  • X427 = inverse-in-orthosymmedial-circle of X1112

  • X427 = perspector of orthic and 5th Euler triangles

  • X427 = radical trace of anticomplementary circle and tangential circle

  • X427 = homothetic center of the medial triangle and the 2nd pedal triangle of X4

  • X427 = perspector of 4th Brocard triangle and cross-triangle of ABC and 4th Brocard triangle

  • X427 = perspector of ABC and cross-triangle of ABC and 5th Euler triangle

  • X427 = harmonic center of nine-point circle and circle O(PU(4))

  • X427 = orthic-isogonal conjugate of X1843

  • X427 = intersection of tangents to Hatzipolakis-Lozada hyperbola at X4 and X6

  • X427 = crosspoint, wrt orthic triangle, of X4 and X6

  • X427 = excentral-to-ABC functional image of X56

  • X427 = intersection of tangents to Walsmith rectangular hyperbola at X113 and X125

  • X427 = barycentric product Xi*Xj for these {i,j}: {1, 20883}, {4, 141}, {6, 1235}, {10, 17171}, {19, 1930}, {25, 8024}, {27, 15523}, {37, 16747}, {38, 92}, {39, 264}, {69, 27376}, {75, 17442}, {76, 1843}, {86, 21016}, {95, 27371}, {107, 2525}, {112, 23285}, {190, 21108}, {193, 47730}, {273, 33299}, {278, 3703}, {281, 3665}, {286, 3954}, {297, 20021}, {324, 16030}, {331, 3688}, {343, 19174}, {393, 3933}, {420, 17949}, {468, 31125}, {523, 41676}, {525, 46151}, {648, 826}, {653, 48278}, {811, 8061}, {850, 35325}, {1289, 23881}, {1401, 7017}, {1502, 27369}, {1634, 14618}, {1783, 48084}, {1824, 16703}, {1826, 16887}, {1897, 16892}, {1964, 1969}, {2052, 3917}, {2501, 4576}, {2528, 42396}, {2530, 6335}, {2592, 46166}, {2593, 46167}, {2996, 41584}, {3005, 6331}, {3051, 18022}, {3186, 42551}, {3313, 43678}, {3404, 40703}, {3613, 37125}, {3867, 18840}, {4074, 37892}, {4391, 46152}, {4553, 17924}, {4568, 7649}, {5094, 23297}, {5117, 14617}, {5485, 41585}, {5523, 46165}, {6531, 51371}, {7794, 32085}, {7813, 17983}, {8041, 46104}, {8362, 8801}, {9019, 46105}, {9229, 12143}, {10159, 46026}, {14376, 41375}, {16080, 51360}, {16102, 40889}, {16696, 41013}, {17980, 35540}, {18018, 40938}, {18020, 39691}, {18027, 20775}, {19568, 47847}, {21035, 44129}, {28666, 40425}, {31613, 42394}, {35140, 51434}, {39129, 41361}, {40416, 46508}, {41331, 44161}, {44132, 51869}, {44146, 46154}, {44427, 46155}, {46106, 46147}, {46107, 46148}, {46108, 46149}, {46109, 46150}, {46110, 46153}

  • X427 = barycentric quotient Xi/Xj for these {i,j}: {1, 34055}, {2, 1799}, {3, 28724}, {4, 83}, {6, 1176}, {19, 82}, {25, 251}, {27, 52394}, {28, 52376}, {32, 10547}, {38, 63}, {39, 3}, {53, 17500}, {66, 40404}, {92, 3112}, {107, 42396}, {112, 827}, {141, 69}, {162, 4599}, {225, 18097}, {232, 51862}, {240, 3405}, {264, 308}, {275, 39287}, {276, 41488}, {297, 20022}, {393, 32085}, {420, 40850}, {429, 27067}, {523, 4580}, {648, 4577}, {688, 3049}, {732, 12215}, {811, 4593}, {826, 525}, {1235, 76}, {1401, 222}, {1593, 26224}, {1634, 4558}, {1824, 18098}, {1826, 18082}, {1840, 18099}, {1843, 6}, {1883, 27005}, {1923, 9247}, {1930, 304}, {1964, 48}, {1969, 18833}, {1973, 46289}, {1974, 46288}, {2052, 46104}, {2084, 810}, {2353, 46765}, {2489, 18105}, {2525, 3265}, {2528, 2525}, {2530, 905}, {2971, 51906}, {3005, 647}, {3051, 184}, {3118, 4173}, {3162, 8793}, {3172, 51508}, {3313, 20806}, {3404, 293}, {3575, 10548}, {3665, 348}, {3688, 219}, {3703, 345}, {3787, 3167}, {3867, 3618}, {3914, 18084}, {3917, 394}, {3933, 3926}, {3954, 72}, {4020, 255}, {4074, 37894}, {4553, 1332}, {4568, 4561}, {4576, 4563}, {5064, 39668}, {5094, 10130}, {6292, 7767}, {6331, 689}, {6591, 18108}, {6995, 42037}, {7649, 10566}, {7794, 3933}, {7813, 6390}, {8024, 305}, {8041, 3917}, {8061, 656}, {8362, 3785}, {8711, 22159}, {8735, 18101}, {8750, 4628}, {8754, 34294}, {8791, 9076}, {9019, 22151}, {11105, 29534}, {11205, 22352}, {11325, 38834}, {12143, 384}, {13854, 16277}, {14273, 22105}, {14424, 14417}, {15523, 306}, {16030, 97}, {16318, 21458}, {16696, 1444}, {16747, 274}, {16887, 17206}, {16892, 4025}, {16893, 4121}, {17171, 86}, {17187, 1790}, {17407, 40357}, {17442, 1}, {17980, 733}, {18022, 40016}, {19118, 33632}, {19174, 275}, {19577, 51459}, {19595, 5596}, {19606, 15389}, {20021, 287}, {20775, 577}, {20883, 75}, {21016, 10}, {21035, 71}, {21108, 514}, {21123, 1459}, {21248, 45201}, {21336, 45220}, {21814, 228}, {23208, 10316}, {23285, 3267}, {23642, 11574}, {24006, 18070}, {27369, 32}, {27370, 41334}, {27371, 5}, {27373, 8743}, {27374, 217}, {27376, 4}, {28666, 6292}, {28667, 8788}, {29959, 41614}, {30489, 43697}, {31125, 30786}, {31390, 21637}, {32085, 52395}, {32676, 34072}, {33299, 78}, {35319, 23181}, {35325, 110}, {36794, 41296}, {37125, 1078}, {39284, 39289}, {39691, 125}, {40889, 16095}, {40936, 22061}, {40938, 22}, {40972, 212}, {41267, 2200}, {41272, 14908}, {41331, 14575}, {41375, 17907}, {41584, 193}, {41585, 1992}, {41676, 99}, {42551, 43714}, {44090, 46228}, {45211, 45210}, {46026, 3589}, {46147, 14919}, {46148, 1331}, {46149, 1814}, {46150, 1797}, {46151, 648}, {46152, 651}, {46153, 1813}, {46154, 895}, {46166, 8115}, {46167, 8116}, {46387, 22384}, {46508, 626}, {46509, 8023}, {47730, 2996}, {48084, 15413}, {48278, 6332}, {50521, 22383}, {51360, 11064}, {51371, 6393}, {51434, 1503}, {51869, 248}

  • X427 = {Xi,Xj}-harmonic conjugate of Xk for these (i,j,k): {1, 5090, 12135}, {2, 3, 7499}, {2, 4, 25}, {2, 5, 37439}, {2, 20, 7494}, {2, 22, 6676}, {2, 25, 468}, {2, 468, 52297}, {2, 858, 1368}, {2, 1368, 30739}, {2, 1370, 3}, {2, 1995, 6677}, {2, 3091, 7392}, {2, 3146, 10565}, {2, 3830, 37904}, {2, 3832, 7398}, {2, 4232, 38282}, {2, 5064, 428}, {2, 5133, 5}, {2, 5169, 5133}, {2, 5189, 6636}, {2, 6353, 37453}, {2, 6636, 7495}, {2, 6995, 6353}, {2, 6997, 5020}, {2, 7378, 4}, {2, 7386, 7484}, {2, 7391, 22}, {2, 7392, 11284}, {2, 7394, 1995}, {2, 7396, 7386}, {2, 7398, 40132}, {2, 7408, 4232}, {2, 7409, 6995}, {2, 7485, 140}, {2, 7500, 7493}, {2, 7571, 3628}, {2, 8889, 5094}, {2, 14957, 7467}, {2, 16051, 31255}, {2, 16063, 7485}, {2, 16951, 7807}, {2, 24584, 1375}, {2, 26032, 37099}, {2, 26096, 25494}, {2, 26760, 27028}, {2, 26808, 26967}, {2, 28684, 28664}, {2, 30744, 5159}, {2, 30888, 46531}, {2, 30951, 37370}, {2, 31021, 857}, {2, 31074, 858}, {2, 31099, 1370}, {2, 31105, 31133}, {2, 31152, 43957}, {2, 31857, 31074}, {2, 34603, 10154}, {2, 34609, 7667}, {2, 37174, 37187}, {2, 37349, 13595}, {2, 37353, 37990}, {2, 37362, 37432}, {2, 37456, 4224}, {2, 37913, 52300}, {2, 38282, 52292}, {2, 46336, 16419}, {2, 47314, 8703}, {2, 52284, 8889}, {2, 52285, 10301}, {2, 52299, 52298}, {3, 4, 3575}, {3, 5, 7399}, {3, 25, 21213}, {3, 381, 18420}, {3, 1370, 7667}, {3, 5576, 5}, {3, 18494, 18533}, {3, 18533, 37931}, {3, 31099, 46517}, {3, 34609, 1370}, {3, 44441, 47090}, {4, 5, 235}, {4, 20, 12173}, {4, 24, 6756}, {4, 25, 428}, {4, 28, 37398}, {4, 186, 7576}, {4, 235, 1906}, {4, 381, 10151}, {4, 403, 1596}, {4, 406, 4186}, {4, 429, 1904}, {4, 442, 37376}, {4, 451, 4222}, {4, 458, 460}, {4, 468, 10301}, {4, 469, 430}, {4, 470, 462}, {4, 471, 463}, {4, 475, 4185}, {4, 631, 7487}, {4, 860, 1894}, {4, 1346, 1312}, {4, 1347, 1313}, {4, 1585, 52286}, {4, 1586, 52287}, {4, 1593, 1885}, {4, 1594, 5}, {4, 1595, 1907}, {4, 2476, 431}, {4, 3088, 1593}, {4, 3089, 5198}, {4, 3090, 3089}, {4, 3091, 37197}, {4, 3127, 32588}, {4, 3128, 32587}, {4, 3144, 37390}, {4, 3147, 37122}, {4, 3520, 6240}, {4, 3535, 52291}, {4, 3536, 5200}, {4, 3541, 3}, {4, 3542, 1598}, {4, 3545, 6623}, {4, 4194, 17516}, {4, 4196, 1889}, {4, 4200, 4214}, {4, 4212, 27}, {4, 4213, 14004}, {4, 5064, 52285}, {4, 5094, 468}, {4, 5117, 297}, {4, 5125, 407}, {4, 5136, 1884}, {4, 5142, 429}, {4, 5169, 37981}, {4, 6143, 3518}, {4, 6353, 6995}, {4, 7378, 5064}, {4, 7498, 28076}, {4, 7505, 10594}, {4, 7507, 23047}, {4, 7547, 546}, {4, 7577, 403}, {4, 7714, 7408}, {4, 8889, 2}, {4, 10018, 7715}, {4, 11109, 37226}, {4, 14865, 18560}, {4, 14940, 34484}, {4, 15559, 1595}, {4, 18533, 18494}, {4, 18560, 3627}, {4, 26020, 37432}, {4, 30100, 12225}, {4, 35473, 18559}, {4, 35475, 34797}, {4, 35481, 35480}, {4, 35482, 3520}, {4, 35488, 44226}, {4, 35490, 3853}, {4, 35502, 13488}, {4, 37074, 1529}, {4, 37117, 7511}, {4, 37118, 37458}, {4, 37119, 24}, {4, 37125, 27369}, {4, 37337, 11325}, {4, 37388, 37385}, {4, 37943, 52294}, {4, 38282, 7714}, {4, 44287, 44281}, {4, 44438, 13473}, {4, 44958, 44803}, {4, 52249, 52280}, {4, 52252, 28}, {4, 52280, 6755}, {4, 52284, 5094}, {4, 52288, 6620}, {4, 52290, 52301}, {4, 52295, 1594}, {4, 52296, 21841}, {4, 52299, 6353}, {5, 140, 7405}, {5, 858, 30739}, {5, 1368, 2}, {5, 1595, 4}, {5, 1596, 403}, {5, 1906, 45004}, {5, 1907, 1906}, {5, 3627, 15761}, {5, 3845, 46030}, {5, 6823, 13160}, {5, 13371, 11585}, {5, 15559, 1907}, {5, 15687, 11563}, {5, 15809, 25}, {5, 23335, 3}, {5, 44960, 16868}, {6, 66, 26926}, {6, 1853, 1899}, {6, 1899, 11245}, {20, 13160, 6823}, {22, 6676, 44210}, {22, 31133, 7391}, {22, 31236, 2}, {22, 37353, 46029}, {24, 37119, 140}, {25, 428, 10301}, {25, 5064, 4}, {25, 5094, 2}, {25, 7378, 52285}, {25, 37453, 6353}, {25, 52298, 37453}, {33, 5101, 1862}, {39, 27371, 27376}, {51, 125, 13567}, {53, 3815, 232}, {54, 34224, 31804}, {115, 1560, 44467}, {125, 132, 47202}, {140, 6756, 24}, {140, 10691, 7485}, {140, 11548, 2}, {140, 16198, 6756}, {140, 47315, 16063}, {140, 50138, 5}, {141, 1843, 41584}, {141, 3867, 1843}, {154, 36990, 31383}, {185, 3574, 12233}, {186, 7576, 37458}, {186, 37118, 549}, {230, 6748, 10311}, {235, 1907, 4}, {235, 30739, 468}, {235, 44960, 44995}, {235, 45003, 44996}, {264, 18022, 42394}, {264, 51843, 18022}, {275, 23295, 8901}, {343, 45303, 21243}, {378, 35480, 35481}, {378, 37970, 3520}, {378, 44269, 18570}, {378, 44274, 44281}, {378, 45179, 15760}, {381, 1597, 4}, {381, 2072, 5}, {381, 5020, 6997}, {381, 30771, 5020}, {382, 7493, 37899}, {382, 9909, 7500}, {393, 7736, 45141}, {403, 1594, 7577}, {403, 1596, 235}, {403, 7577, 5}, {428, 468, 25}, {428, 5094, 52297}, {428, 8889, 52293}, {428, 52285, 4}, {429, 1883, 4}, {442, 8226, 7522}, {465, 41034, 3132}, {466, 41035, 3131}, {468, 5094, 52293}, {468, 52285, 428}, {470, 471, 52289}, {470, 472, 16250}, {471, 473, 16249}, {472, 473, 52281}, {546, 5159, 1995}, {546, 10224, 5}, {546, 13488, 4}, {549, 37458, 186}, {578, 18381, 6146}, {590, 5412, 13884}, {615, 5413, 13937}, {631, 7487, 3515}, {631, 44831, 44837}, {858, 1594, 5094}, {858, 2072, 47097}, {858, 5133, 2}, {858, 5169, 5}, {858, 5576, 37454}, {858, 7378, 15809}, {858, 31099, 23335}, {858, 37981, 468}, {858, 46698, 1312}, {858, 46699, 1313}, {867, 37354, 8727}, {1113, 1114, 21284}, {1125, 49542, 11363}, {1204, 6696, 43903}, {1312, 1313, 468}, {1346, 1347, 5094}, {1346, 46699, 5}, {1347, 46698, 5}, {1368, 1595, 15809}, {1368, 5133, 37439}, {1370, 31099, 34609}, {1370, 34609, 46517}, {1513, 52280, 25}, {1585, 1586, 458}, {1593, 7507, 4}, {1593, 18386, 44438}, {1594, 1595, 235}, {1594, 15559, 4}, {1594, 15809, 37439}, {1595, 52284, 30739}, {1596, 16868, 45000}, {1597, 52284, 47097}, {1598, 1656, 3542}, {1656, 16419, 2}, {1656, 50137, 5}, {1799, 16275, 7750}, {1843, 46026, 3867}, {1848, 1861, 1824}, {1883, 5142, 1904}, {1885, 13473, 44438}, {1885, 23047, 4}, {1907, 37439, 428}, {1994, 3448, 45968}, {1994, 45968, 1353}, {1995, 30744, 2}, {2041, 2042, 9715}, {2052, 6530, 14569}, {2071, 38323, 44241}, {2450, 37988, 5}, {2476, 37983, 5}, {2479, 2480, 40889}, {2969, 7140, 92}, {2979, 37636, 48876}, {3060, 3580, 41588}, {3060, 7703, 23293}, {3060, 23293, 3580}, {3088, 7507, 1885}, {3091, 16051, 11284}, {3091, 37197, 10019}, {3127, 3128, 4}, {3146, 10565, 34608}, {3147, 37122, 3517}, {3148, 14003, 441}, {3153, 7527, 52069}, {3162, 13854, 16318}, {3258, 42426, 47223}, {3516, 12173, 20}, {3517, 3526, 3147}, {3518, 6143, 10018}, {3518, 7496, 37920}, {3520, 6240, 550}, {3547, 34938, 11414}, {3548, 7528, 6642}, {3567, 23294, 26879}, {3575, 7499, 21213}, {3575, 37454, 468}, {3575, 37931, 18533}, {3627, 45177, 235}, {3628, 10300, 40916}, {3628, 21841, 7505}, {3628, 50136, 5}, {3830, 7579, 10254}, {3830, 10254, 11799}, {3832, 30769, 40132}, {3839, 30775, 47597}, {3850, 44226, 35488}, {3850, 49673, 5}, {3851, 50143, 5}, {3853, 37897, 7519}, {4074, 40379, 141}, {4232, 7408, 7714}, {4232, 7714, 25}, {4232, 52292, 468}, {5000, 5001, 5}, {5002, 5003, 12225}, {5004, 5005, 7488}, {5020, 30771, 2}, {5055, 50135, 5}, {5064, 5094, 25}, {5064, 8889, 468}, {5064, 37439, 1906}, {5064, 52292, 7408}, {5064, 52298, 6995}, {5066, 50140, 5}, {5072, 50139, 5}, {5094, 7378, 428}, {5094, 37197, 11284}, {5094, 37453, 52298}, {5094, 37920, 6143}, {5094, 37981, 5}, {5094, 52298, 52299}, {5133, 15559, 5064}, {5133, 15809, 235}, {5133, 31074, 1368}, {5133, 37990, 37353}, {5159, 6677, 2}, {5169, 31074, 2}, {5169, 31101, 37353}, {5169, 31857, 858}, {5169, 40916, 50136}, {5169, 46336, 50137}, {5169, 52284, 1594}, {5189, 6636, 52397}, {5189, 7495, 550}, {5422, 18911, 45298}, {5446, 5449, 41587}, {5480, 13567, 51}, {5480, 23332, 13567}, {5576, 23335, 7399}, {6143, 10018, 632}, {6240, 7495, 21284}, {6247, 12233, 185}, {6353, 6995, 25}, {6353, 7577, 37990}, {6353, 8889, 52299}, {6353, 35481, 22}, {6353, 37453, 468}, {6353, 52299, 2}, {6623, 32216, 468}, {6636, 52397, 550}, {6639, 7517, 13383}, {6640, 7506, 16238}, {6640, 44259, 44907}, {6643, 7404, 7395}, {6644, 18281, 10257}, {6676, 13413, 37990}, {6696, 13568, 1204}, {6747, 42400, 53}, {6756, 16198, 4}, {6776, 11427, 11402}, {6995, 7378, 7409}, {6995, 7391, 35480}, {6995, 7409, 4}, {6995, 8889, 52298}, {6995, 37353, 403}, {6995, 52298, 468}, {6995, 52299, 37453}, {7378, 8889, 25}, {7378, 15809, 1907}, {7378, 52284, 2}, {7386, 7396, 31152}, {7386, 7484, 43957}, {7386, 28412, 426}, {7391, 31236, 6676}, {7392, 11403, 428}, {7392, 16051, 2}, {7394, 30744, 6677}, {7396, 7539, 43957}, {7398, 30769, 2}, {7400, 52398, 37198}, {7403, 11585, 5}, {7408, 38282, 25}, {7409, 8889, 37453}, {7409, 37453, 428}, {7409, 37990, 1596}, {7409, 52284, 52299}, {7409, 52299, 25}, {7418, 46591, 21284}, {7484, 7539, 2}, {7484, 31152, 7386}, {7485, 16063, 10691}, {7493, 7500, 9909}, {7494, 44442, 20}, {7495, 52397, 6636}, {7499, 7667, 3}, {7499, 37454, 2}, {7499, 46517, 7667}, {7500, 9909, 37899}, {7503, 37444, 12362}, {7505, 10594, 21841}, {7505, 52296, 3628}, {7507, 44438, 18386}, {7514, 31181, 14791}, {7526, 18569, 12605}, {7530, 10201, 37971}, {7536, 49132, 199}, {7539, 31152, 7484}, {7542, 7553, 26}, {7544, 17928, 9825}, {7547, 35502, 4}, {7558, 10323, 16197}, {7566, 17928, 7544}, {7569, 10323, 7558}, {7570, 37977, 14940}, {7571, 40916, 2}, {7576, 37118, 186}, {7577, 18533, 37347}, {7577, 31101, 52298}, {7577, 35480, 46029}, {7579, 11799, 5}, {7592, 11457, 18914}, {7667, 37454, 7499}, {7667, 46517, 1370}, {7714, 38282, 4232}, {8370, 35920, 15014}, {8889, 15559, 15809}, {8889, 15809, 30739}, {8889, 52285, 52297}, {8891, 21248, 141}, {9777, 26869, 11433}, {9786, 40686, 26937}, {9818, 18531, 34664}, {9825, 16196, 17928}, {9909, 18364, 6636}, {10109, 50134, 5}, {10151, 47097, 468}, {10295, 35473, 8703}, {10301, 52293, 468}, {10594, 52296, 7505}, {10691, 11548, 140}, {11056, 16275, 1799}, {11284, 31255, 2}, {11381, 43831, 2883}, {11403, 37197, 4}, {11410, 37196, 376}, {11427, 32064, 6776}, {11432, 26944, 18916}, {11433, 14853, 9777}, {11433, 23291, 26869}, {11548, 47315, 10691}, {11572, 21659, 41362}, {11737, 50142, 5}, {11818, 18281, 6644}, {12086, 34007, 52071}, {12100, 37934, 35472}, {12106, 44452, 44211}, {13371, 33332, 7403}, {13413, 46029, 5}, {13490, 44452, 12106}, {13567, 23332, 125}, {14130, 31724, 18563}, {14782, 14783, 7401}, {14784, 14785, 3547}, {14813, 14814, 34002}, {14826, 37669, 6090}, {14853, 23291, 11433}, {15033, 25739, 12022}, {15559, 52295, 5}, {16051, 37197, 468}, {16238, 32144, 6640}, {16252, 16621, 26883}, {16387, 44260, 44210}, {17111, 23304, 11}, {18386, 44438, 4}, {18420, 44441, 3}, {18494, 18533, 3575}, {18559, 35473, 10295}, {18560, 45177, 15761}, {18570, 44236, 44218}, {18570, 44249, 44285}, {18570, 44269, 44281}, {18570, 44274, 44269}, {18570, 44287, 44236}, {18583, 45298, 5422}, {19041, 19042, 40065}, {21213, 37454, 52297}, {21850, 41588, 3060}, {23336, 31830, 37814}, {24886, 24939, 2}, {25738, 36749, 13292}, {25985, 26020, 2}, {25985, 37362, 25}, {27098, 27150, 2}, {27386, 27510, 33305}, {28020, 28084, 33302}, {28048, 28126, 33306}, {28240, 28354, 859}, {28412, 28701, 441}, {29385, 29442, 46497}, {29498, 29701, 46575}, {29553, 29752, 46574}, {29970, 30040, 46514}, {30739, 37439, 2}, {31074, 37353, 31101}, {31099, 52284, 3541}, {31101, 37353, 2}, {31105, 52284, 378}, {31133, 31236, 22}, {31236, 35480, 37453}, {31670, 37638, 47582}, {31723, 52262, 44239}, {32587, 32588, 4}, {34221, 34222, 19161}, {34797, 35475, 35491}, {34797, 35491, 15704}, {35471, 35477, 548}, {35480, 52299, 6676}, {35487, 44803, 44958}, {35502, 52295, 10224}, {37353, 37990, 5}, {37452, 50137, 1656}, {37453, 52298, 2}, {37454, 46517, 3}, {37472, 44076, 43595}, {39504, 46029, 13413}, {42789, 42790, 35921}, {43957, 47311, 31152}, {44218, 44249, 18570}, {44236, 44288, 44249}, {44287, 44288, 18570}, {44637, 44638, 6748}, {44996, 45003, 45006}, {46517, 47097, 47090}, {46698, 46699, 37981}, {47090, 47310, 47340}, {47612, 47613, 11585}, {52286, 52287, 460}, {52293, 52297, 2}

Notes

As a point on the Euler line, X427 has Shinagawa coefficients \((F,E + F)\).

Let LA be the line tangent to the nine-point circle at the midpoint of segment BC, and define LB and LC cyclically. The triangle formed by the lines LA, LB, LC is homothetic to the orthic triangle, and the center of homothety is X427. (Randy Hutson, 9/23/2011)

Let (O) be the circumcircle, (N) the nine-point circle, and (IA, (IB, (IC the excircles of ABC. Let A' and A″ be the points of intersection of (O) and (IA. Let FA be the touchpoint of (N) and (IA, and let (KA) be the circle through A' and A″ that is internally tangent to (N); let LA be the touchpoint. Define FB, FC and LB, LC cyclically. The lines FALA, FBLB, FCLC concur ion X427. (Tran Quang Hung ADGEOM #1458, August 5, 2014; see also #1459)

Let CmaCmbCmc be the circummedial triangle. Let A″ be the pole, wrt the polar circle, of line CmbCmc, and define B″ and C″ cyclically. The lines AA″, BB″, CC″ concur in X427. Moreover, X427 is the Euler line intercept of radical axis of nine-point circle and every circle with center on orthic axis that is orthogonal to nine-point circle, and X427 is the point in which the extended trapezoid legs (P(4),P(4)-Ceva conjugate of U(4)) and (U(4),U(4)-Ceva conjugate of P(4)) meet. Also, X427 is the QA-P38 center (Montesdeoca-Hutson Point) of quadrangle ABCX2. (Randy Hutson, October 13, 2015)

X427 is the homothetic center of any pair of the following: polar triangle of nine-point circle, orthic axes triangle (see X2501), Yiu tangents triangle (see X7495). (Randy Hutson, August 19, 2019)