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USAMO 2025 — Days 1 and 2 Question 4

USAMO · USAMO 2025 — Days 1 and 2

Question 4

Let $H$ be the orthocenter of an acute triangle $ABC$,
let $F$ be the foot of the altitude from $C$ to $AB$,
and let $P$ be the reflection of $H$ across $BC$.
Suppose that the circumcircle of triangle $AFP$ intersects line $BC$
at two distinct points $X$ and $Y$.
Prove that $CX = CY$.

Proposed by Carl Schildkraut.

Manual essay; 1 editorial point, not official contest scoring. Automatic answer fields are intentionally empty.