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MathNet 2023-part-05 — 191 problems (EN–VI) Question 153

Math Olympiad Vault · MathNet 2023-part-05 — 191 problems (EN–VI)

Question 153

Let $ABC$ be a triangle with $\angle B = 2\angle C$ and angle bisector $BD$. The symmedian of vertex $B$ in triangles $DAB$, $BCD$ cuts the corresponding circumcircle at $M$, $N$. Denote $P$ as the reflection of $B$ over $C$. Prove that the circle $(MNP)$ is tangent to $BC$ and both of circles $(DAB), (BCD)$.