X3612¶
INTERSECTION OF LINES X1X_3 AND X21X_90
Let Ja, Jb, Jc be the excenters and I the incenter. Let A' be the centroid of JbJcI, and define B' and C' cyclically. A'B'C' is also the cross-triangle of the excentral and 2nd circumperp triangles. A'B'C' is homothetic to the reflection triangle of X1 at X3612. (Randy Hutson, July 31 2018)
X3612 (INTERSECTION OF LINES X1X_3 AND X21X_90) constructed on acute reference triangle \((a, b, c) = (5, 6, 7)\) with unit baseline AB = \(1\).¶
Constructed Elements
Central Lines: {1, 3}, {21, 90}
Related Centers: X1 (INCENTER), X3 (CIRCUMCENTER), X21 (SCHIFFLER POINT), X90 (-CROSS CONJUGATE OF X1)
Trilinears: \(3 \cos A + \cos B + \cos C : :\)
Search Value (6, 9, 13): \(3.068868072161\)