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MathNet 2025-part-01 — 187 problems (EN–VI) Question 49

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

Question 49

In an acute triangle $ABC$, the extension of the altitude $AD$ over $D$ intersects the circumcircle at $E$. The midpoint of $CE$ is $F$. The circumcircles of $ABC$ and $DEF$ intersect at $G \neq E$. The foot of the altitude drawn from $A$ to $FG$ is $P$. Prove that $DA = DP$.