Intersection of circumcircles of MNP and BOC
Source: Serbian National Olympiad 2013, Problem 3
April 8, 2013
geometrycircumcircletrigonometryratiosymmetrygeometric transformationreflection
Problem Statement
Let , and be midpoints of sides and , respectively, and let be circumcenter of acute-angled triangle . Circumcircles of triangles and intersect at two different points and inside of triangle . Prove that