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MathNet 2009-part-05 — 172 problems (EN–VI) Question 33

Math Olympiad Vault · MathNet 2009-part-05 — 172 problems (EN–VI)

Question 33

Let $\omega$ be a circle of radius $1$ centered at $O$. Let $B$ be a point on $\omega$, and let $l$ be the line tangent to $\omega$ at $B$. Let $A$ be on $l$ such that $\angle A O B = 60^\circ$. Let $C$ be the foot of the perpendicular from $B$ to $O A$. Find the length of line segment $O C$.