Let ABCD be a quadrilateral inscribled in a circle with the center O,P be the point of intersection of the diagonals AC and BD, BC∦AD. Rays AB and DC intersect at the point E. The circle with center I inscribed in the triangle EBC touches BC at point T1. The E-excircle with center J in the triangle EAD touches the side AD at the point T2. Line IT1 and JT2 intersect at Q. Prove that the points O,P, and Q lie on a straight line. geometrycyclic quadrilateralcollinearincircleexcircle