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MathNet 2008-part-01 — 165 problems (EN–VI) Question 47

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

Question 47

Let $\Gamma$ be the circumcircle of a triangle $A B C$. A circle passing through points $A$ and $C$ meets the sides $B C$ and $B A$ at $D$ and $E$, respectively. The lines $A D$ and $C E$ meet $\Gamma$ again at $G$ and $H$, respectively. The tangent lines of $\Gamma$ at $A$ and $C$ meet the line $D E$ at $L$ and $M$, respectively. Prove that the lines $L H$ and $M G$ meet on $\Gamma$.