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MathNet 2015-part-05 — 191 problems (EN–VI) Question 140

Math Olympiad Vault · MathNet 2015-part-05 — 191 problems (EN–VI)

Question 140

Let $D$ and $E$ be the midpoints of sides $BC$ and $CA$ of the triangle $ABC$ respectively. The lines $AD$ and $BE$ intersect the circumcircle of the triangle $ABC$ additionally in points $P$ and $Q$ respectively. Suppose that $|DP| = |EQ|$. Prove that the triangle $ABC$ is isosceles with apex $C$.