MathDB
Equal Angles

Source: 2018 China North Mathematical Olympiad Grade 10 Test 2 P2

July 26, 2018
geometryChinacircumcircle

Problem Statement

Let HH be the orthocenter of triangle ABCABC. Let DD and EE be points on ABAB and ACAC such that DEDE is parallel to CHCH. If the circumcircle of triangle BDHBDH passes through MM, the midpoint of DEDE, then prove that ∠ABM=∠ACM\angle ABM=\angle ACM
Back to ProblemsView on AoPS