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MathNet 2025 — 50 problems with figures (EN–VI) Question 33

Math Olympiad Vault · MathNet 2025 — 50 problems with figures (EN–VI)

Question 33

Let $\omega_{1}$ and $\omega_{2}$ be two circles intersecting at distinct points $A$ and $B$. Point $X$ varies along $\omega_{1}$, and point $Y$ on $\omega_{2}$ is chosen such that $AB$ bisects the angle $\angle XAY$. Prove that as $X$ varies along $\omega_{1}$, the circumcenter of $\triangle AXY$ (if it exists) varies along a fixed line.