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MathNet 2008-part-01 — 165 problems (EN–VI) Question 140

Math Olympiad Vault · MathNet 2008-part-01 — 165 problems (EN–VI)

Question 140

In $\triangle ABC$, $AB = AC$, the inscribed circle $I$ touches $BC$, $CA$, $AB$ at points $D$, $E$ and $F$ respectively. $P$ is a point on arc $\widehat{EF}$ (not containing $D$). Line $BP$ intersects the circle $I$ at another point $Q$, and lines $EP$, $EQ$ meet line $BC$ at $M$, $N$ respectively. Prove that

(1) $P$, $F$, $B$, $M$ are concyclic;

$$
(2) \frac{EM}{EN} = \frac{BD}{BP}.
$$