X572¶
ORTHOGONAL OF X58
X572 (ORTHOGONAL OF X58) constructed on acute reference triangle \((a, b, c) = (5, 6, 7)\) with unit baseline AB = \(1\).¶
Constructed Elements
Central Lines: {3, 6}, {9, 48}
Related Centers: X2051 (EXSIMILICENTER), X3 (CIRCUMCENTER), X6 (SYMMEDIAN POINT), X9 (MITTENPUNKT), X48 (CROSSPOINT OF X1 AND X63)
Trilinears: \(f(A,B,C) : f(B,C,A) : f(C,A,B)\), where \(f(A,B,C) = \cos(A - U)\), where cot \(U = \cot(A/2) \cot(B/2) \cot(C/2)\) (Joe Goggins, 11/26/08)
Search Value (6, 9, 13): \(5.234901251064\)
Alternate Coordinates3 forms
Trilinears: \(g(A,B,C) : g(B,C,A) : g(C,A,B)\), where \(g(A,B,C) = \sin A + \cot D/2 \cos A\), cot \(D/2 = (a + b + c)^{2}/(4 \operatorname{area})\)
Trilinears: \(s \cos A + r \sin A : :\)
Trilinears: \(a (a^{3} - a (b^{2} - b c + c^{2}) - b c (b + c)) : :\)
Incident Central Lines14 lines
Functional Relations4 relations
Notes¶
X572 is the intersection of the Brocard axes of ABC, the Feuerbach triangle, and the Apollonius triangle. (Randy Hutson, March 21, 2019)