X1109¶
TRILINEAR SQUARE OF X523
X1109 (TRILINEAR SQUARE OF X523) constructed on acute reference triangle \((a, b, c) = (5, 6, 7)\) with unit baseline AB = \(1\).¶
Constructed Elements
Central Lines: {31, 92}, {91, 255}
Related Centers: X1101 (TRILINEAR SQUARE OF X110), X31 (2nd POWER POINT), X92 (CEVAPOINT OF INCENTER AND CLAWSON POINT), X91 (ISOGONAL CONJUGATE OF X47), X255 (ISOGONAL CONJUGATE OF X158)
Alternate Coordinates1 form
Trilinears: \(1 - \cos(2B - 2C) : :\)
Functional Relations14 relations
X1109 = isogonal conjugate of X1101
X1109 = complement of X6758
X1109 = anticomplement of X16598
X1109 = crosssum of Xi and Xj for these (i,j): (31, 163), (60, 110)
X1109 = crossdifference of every pair of points on line X163X1983
X1109 = bicentric difference of PU(73)
X1109 = polar conjugate of isotomic conjugate of X20902
Notes¶
X1109: Let EuaEubEuc be the Feuerbach triangle. Let La be the trilinear polar of Eua, and define Lb, Lc cyclically. Let A″ = Lb∩Lc, B″ = Lc∩La, C″ = La∩Lb. The lines AA″, BB″, CC″ concur in X1109. (Randy Hutson, December 26, 2015)
Let EuaEubEuc be the Feuerbach triangle. Let Ma be the tangent to conic {{A, B, C,Eub,Euc}} at A, and define Mb and Mc cyclically. Let A* = Mb∩Mc, B* = Mc∩Ma, C* = Ma∩Mb. The lines AA*, BB*, CC* concur in X1109; see also X523. (Randy Hutson, December 26, 2015)
Let EuaEubEuc be the Feuerbach triangle. Let Ab = BC∩EucEua, and define Bc and Ca cyclically. Let Ac = BC∩EuaEub, and define Ba and Cb cyclically. The points Ab, Ac, Bc, Ba, Ca, Cb lie on an ellipse, denoted by E. Let A″ be the intersection of the tangents to E at Ba and Ca, and define B″ and C″ cyclically. The lines AA″, BB″, CC″ concur in X1109. (Randy Hutson, December 26, 2015)
Let EuaEubEuc be the Feuerbach triangle. Let A″ be the trilinear product Eub*Euc, and define B″ and C″ cyclically. The lines AA″, BB″, CC″ concur in X1109. (Randy Hutson, December 26, 2015)
Let La be the A-extraversion of line X2610X4024 (the trilinear polar of X12), and define Lb and Lc cyclically. Let A' = Lb ∩ Lc, and define B' and C' cyclically. The lines AA', BB', CC' concur in X1109. (Randy Hutson, January 29, 2018)
Let F be the Feuerbach point, X11, and FaFbFc be the Feuerbach triangle (the extraversion triangle of X11). Let A' be the trilinear product F*Fa, and define B' and C' cyclically. The lines AA', BB', CC' concur in X1109. (Randy Hutson, January 29, 2018)