Let ABCABC be an acute-angled triangle with BAC>45°\measuredangle BAC > 45° and with circumcentre OO. The point PP lies in its interior such that the points A,P,O,BA, P, O, B lie on a circle and BPBP is perpendicular to CPCP. The point QQ lies on the segment BPBP such that AQAQ is parallel to POPO.

Prove that QCB=PCO\measuredangle QCB = \measuredangle PCO.