Cyclic quadrilateral bisectors
Source: Moldova TST 2014, Second Day, Problem 3
March 30, 2014
geometrycircumcircletrapezoidgeometry proposed
Problem Statement
Let be a cyclic quadrilateral. The bisectors of angles and intersect in point such that . Let be the midpoint of . A line passing through point and parallel to intersects in point . Prove that triangle is isosceles.