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Circle Time
Age 14 to 16
ShortChallenge Level 
Three circles C_1, C_2 and C_3, of radii 1 cm, 2 cm and 3 cm respectively touch as shown. C_1 meets C_2 at P and meets C_3 at Q.
What is the length in cm of the longer arc of circle C_1 between P and Q?
If you liked this problem, here is an NRICH task which challenges you to use similar mathematical ideas.
This problem is taken from the UKMT Mathematical Challenges.
You can find more short problems, arranged by curriculum topic, in our short problems collection.
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