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MathNet 2023-part-04 — 191 problems (EN–VI) Question 31

Math Olympiad Vault · MathNet 2023-part-04 — 191 problems (EN–VI)

Question 31

Let $ABC$ be an acute triangle, where the altitudes $BD$ and $CE$ are drawn. Let $L$ be the point on segment $BD$ such that $AD = DL$, and let $K$ be the point on segment $CE$ such that $AE = EK$. Denote $M$ as the midpoint of segment $KL$. The circumcircle of triangle $ABC$ intersects line $AL$ again at point $T$ and line $AK$ again at point $S$. Prove that the lines $BS$, $CT$, and $AM$ are concurrent.