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MathNet 2015-part-02 — 191 problems (EN–VI) Question 170

Math Olympiad Vault · MathNet 2015-part-02 — 191 problems (EN–VI)

Question 170

Let $ABC$ be a triangle, and $\Gamma$ its circumcircle. Let $M$ be the midpoint of the arc $BC$ not containing $A$. A circle $\mathscr{C}$ is tangent to the rays $[AB)$ and $[AC)$ at $D$ and $E$ respectively, and internally tangent to $\Gamma$ at $F$. Show that $(DE)$, $(BC)$ and $(FM)$ are concurrent.