MathDB
prove an identity

Source: Ireland 1999

July 4, 2009
geometryangle bisectorgeometry proposed

Problem Statement

If AD AD is the altitude, BE BE the angle bisector, and CF CF the median of a triangle ABC ABC, prove that AD,BE, AD,BE, and CF CF are concurrent if and only if: a^2(a\minus{}c)\equal{}(b^2\minus{}c^2)(a\plus{}c), where a,b,c a,b,c are the lengths of the sides BC,CA,AB BC,CA,AB, respectively.