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MathNet 2025-part-01 — 187 problems (EN–VI) Question 46

Math Olympiad Vault · MathNet 2025-part-01 — 187 problems (EN–VI)

Question 46

Let $O$ be the circumcentre of an acute triangle $ABC$. Points $D$ and $E$ are chosen on the side $BC$ such that $AD$ is an altitude of the triangle $ABC$ and $AE$ bisects the angle $CAD$. Bisectors of the triangle $AOB$ meet at point $J$. Prove that the triangle $JBE$ is isosceles.