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MathNet 1998 — Part 01 Question 45

Math Olympiad Vault · MathNet 1998 — Part 01

Question 45

$I$ is the incentre of $\triangle ABC$. $P, Q, R$ are the circumcentres of the triangles $IBC, ICA$ and $IAB$ respectively. Prove that the points $A, R, B, P, C, Q$ are concyclic.