IMO 2007 Shortlist G3

The diagonals of a trapezoid ABCD intersect at point P. Point Q lies between the parallel lines BC and AD such that ∠AQD...

IMO 2007 Shortlist G3

Category: Geometry

Problem

The diagonals of a trapezoid ABCD intersect at point P. Point Q lies between the parallel lines BC and AD such that ∠AQD = ∠CQB, and line CD separates points P and Q. Prove that ∠BQP = ∠DAQ. (Ukraine)