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MathNet 2019-part-01 — 184 problems (EN–VI) Question 91

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

Question 91

Let $ABC$ be a triangle and $H$ its orthocenter. Point $D$ lies on segment $AC$ and $E$ is its foot onto the line $BC$. Prove that $EH \perp BD$ iff $BD$ bisects $AE$.