MathDB
Congruent Triangles

Source: ToT - 2001 Spring Senior A-Level #3

August 17, 2011
geometryparallelogramgeometry unsolved

Problem Statement

Let AHAAH_A, BHBBH_B and CHCCH_C be the altitudes of triangle ABC\triangle ABC. Prove that the triangle whose vertices are the intersection points of the altitudes of AHBHC\triangle AH_BH_C, BHAHC\triangle BH_AH_C and CHAHB\triangle CH_AH_B is congruent to HAHBHC\triangle H_AH_BH_C.