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MathNet 2012 Question 47

Math Olympiad Vault · MathNet 2012

Question 47

Let $ABC$ be a triangle with incenter $I$ and circumcenter $O$ and let $M$ be the midpoint of $BC$. The bisector of angle $A$ intersects lines $BC$ and $OM$ at $L$ and $Q$, respectively. Prove that
$$
AI \cdot LQ = IL \cdot IQ.
$$