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MathNet 2019-part-01 — 184 problems (EN–VI) Question 90

Math Olympiad Vault · MathNet 2019-part-01 — 184 problems (EN–VI)

Question 90

Let $ABC$ be a scalene triangle. Let $P$ be an interior point of $ABC$ such that $AP \perp BC$. Assume that $BP$ and $CP$ intersect $AC$ and $AB$ at $X$ and $Y$, respectively. Prove that $AX = AY$ iff there exists a circle with centre lying on $BC$ and tangent to $AB$ and $AC$ at points $Y$ and $X$, respectively.