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MathNet 2023-part-01 — 191 problems (EN–VI) Question 189

Math Olympiad Vault · MathNet 2023-part-01 — 191 problems (EN–VI)

Question 189

In the convex pentagon $ABCDE$, $|\angle CBA| = |\angle BAE| = |\angle AED|$ holds. On the sides $AB$ and $AE$, there are points $P$ and $Q$, respectively, such that $|AP| = |BC| = |QE|$ and $|AQ| = |BP| = |DE|$. Prove that $CD \parallel PQ$. (Patrik Bak)