2020 IGO Intermediate P3
Source: 7th Iranian Geometry Olympiad (Intermediate) P3
November 4, 2020
geometrycircumcircleorthocenterIGO
Problem Statement
In acute-angled triangle (), point is the orthocenter and point is the midpoint of the segment . The median intersects the circumcircle of triangle at . The line intersects the perpendicular bisector of at and the circumcircle of the triangle again at . Point lies on circle , passing through and , such that is a trapezoid (). Prove that and meet on .
Proposed by Alireza Dadgarnia