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MathNet 2020 — Math Olympiad Vault — Part 06 Question 16

Math Olympiad Vault · MathNet 2020 — Math Olympiad Vault — Part 06

Question 16

Let $ABC$ be a triangle with $AB\lt AC$, and let $I$ be its incenter. The incircle touches $BC$ at $D$. Let $E$ be the unique point such that $D$ is the midpoint of $BE$. The line through $E$ perpendicular to $BC$ meets $CI$ at $P$. Prove that $BP\perp AD$.