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MathNet 2016-part-02 — 184 problems (EN–VI) Question 125

Math Olympiad Vault · MathNet 2016-part-02 — 184 problems (EN–VI)

Question 125

Let $ABC$ be an acute-angled triangle with $\Varangle BAC \gt 45^{\circ}$ and with circumcentre $O$. The point $P$ lies in its interior such that the points $A, P, O, B$ lie on a circle and $BP$ is perpendicular to $CP$. The point $Q$ lies on the segment $BP$ such that $AQ$ is parallel to $PO$.
Prove that $\Varangle QCB = \Varangle PCO$.

Question illustration