collinear wanted, ABCD parallllogram tangents of circumcircle of MAD,MBC
Source: 2020 Czech-Polish-Slovak Match p1
October 8, 2020
geometryparallelogramcircumcircleComputer problems
Problem Statement
Let be a parallelogram whose diagonals meet at . Denote by the midpoint of . Let be a point such that is tangent to the circumcircle of and is tangent to the circumcircle of . Prove that points are collinear. (Patrik Bak, Slovakia)