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MathNet 2007-part-01 — 187 problems (EN–VI) Question 21

Math Olympiad Vault · MathNet 2007-part-01 — 187 problems (EN–VI)

Question 21

In a triangle $ABC$, $\hat{A} = 2\hat{C}$ and $2\hat{B} = \hat{A} + \hat{C}$. The bisector of angle $\hat{C}$ meets side $AB$ at $E$, and $F$ is the midpoint of segment $AE$. The altitude to side $BC$ is $AD$. The perpendicular bisector of segment $DF$ meets side $AC$ at $M$.
Prove that $AM = CM$.