Vertex on radical axis
Source: Sharygin geometry olympiad 2016, grade 10, Final Round, Problem 1.
August 5, 2016
geometrycircumcircleSharygin Geometry Olympiad
Problem Statement
A line parallel to the side of a triangle meets the sides and at points and , respectively. A point is chosen inside the triangle . The segments and meet the segment at points and , respectively. Let be the second intersection point of the circumcircles of the triangles and . Prove that the points are collinear.