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MathNet 2017-part-04 — 176 problems (EN–VI) Question 25

Math Olympiad Vault · MathNet 2017-part-04 — 176 problems (EN–VI)

Question 25

Given is a circle $\omega$ with diameter $A K$. Point $M$ lies inside the circle, not on line $A K$. The line $A M$ intersects $\omega$ again at $Q$. The tangent to $\omega$ at $Q$ intersects the line through $M$ perpendicular to $A K$ at $P$. Point $L$ lies on $\omega$ such that $P L$ is a tangent, with $L \neq Q$. Prove that $K, L$ and $M$ are collinear.

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