Maths Olympiad Prep

Library / /44 of 48

Geometry Difficulty 5.5 AIME, harder Prove it United States

Problem:
A circle with center at OO has radius 11. Points PP and QQ outside the circle are placed such that PQPQ passes through OO. Tangent lines to the circle through PP hit the circle at P1P_{1} and P2P_{2}, and tangent lines to the circle through QQ hit the circle at Q1Q_{1} and Q2Q_{2}. If P1PP2=45\angle P_{1} P P_{2} = 45^{\circ} and Q1QQ2=30\angle Q_{1} Q Q_{2} = 30^{\circ}, find the minimum possible length of arc P2Q2P_{2} Q_{2}.

Solution

Solution:
(4530)=π12.(45-30)^{\circ} = \frac{\pi}{12}.

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Source: MathNet, licensed CC-BY-4.0. Statement reproduced verbatim; metadata (topic, difficulty) added by this project.