Circumcircle intersections everywhere
Source: Indonesian Mathematical Olympiad 2013 Problem 2
September 5, 2013
geometrycircumcirclegeometry unsolved
Problem Statement
Let be an acute triangle and be its circumcircle. The bisector of intersects at [another point] . Let be a point on and inside . Lines passing that are parallel to and intersects on respectively. Lines intersects at points respectively. Prove that are concurrent.