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MathNet 2012 Question 40

Math Olympiad Vault · MathNet 2012

Question 40

Let $ABC$ be a triangle with orthocentre $H$ and let $P$ be a point on its circumcircle. The line through $A$ parallel to $BP$ meets $CH$ at $Q$ and the line through $A$ parallel to $CP$ meets $BH$ at $R$. Prove that $QR$ is parallel to $AP$.