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MathNet 2018-part-05 — 181 problems (EN–VI) Question 65

Math Olympiad Vault · MathNet 2018-part-05 — 181 problems (EN–VI)

Question 65

Let $ABCD$ be a convex quadrilateral inscribed in circle $(O)$ such that $DB = DA + DC$. The point $P$ lies on the ray $AC$ such that $AP = BC$. The point $E$ is on $(O)$ such that $BE \perp AD$. Prove that $DP$ is parallel to the angle bisector of $\angle BEC$.