MathDB
Prove angles are equal

Source: Canadian Mathematical Olympiad - 1994 - Problem 5.

May 13, 2011
trigonometrygeometry proposedgeometryCanadaanglesTriangle

Problem Statement

Let ABCABC be an acute triangle. Let ADAD be the altitude on BCBC, and let HH be any interior point on ADAD. Lines BH,CHBH,CH, when extended, intersect AC,ABAC,AB at E,FE,F respectively. Prove that ∠EDH=∠FDH\angle EDH=\angle FDH.
Back to ProblemsView on AoPS