2019 Central American and Caribbean Mathematical Olympiad, P3
Source:
June 18, 2019
geometrycircumcircle
Problem Statement
Let be a triangle and its circumcircle. Let be the foot of the altitude from to the side , and the midpoints of and , and the point on diametrically opposite to . Let be the midpoint of . Show that the lines perpendicular to and passing through and , respectively, meet on .