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2006 AMC 12A Question 22

AMC12 · 2006 AMC 12A

Question 22

A circle of radius $r$ is concentric with and outside a regular hexagon of side length $2.$ The probability that three entire sides of the hexagon are visible from a randomly chosen point on the circle is $\frac{1}{2}.$ What is $r?$
  1. $2\sqrt{2} + 2\sqrt{3}$
  2. $3\sqrt{3} + \sqrt{2}$
  3. $2\sqrt{6} + \sqrt{3}$
  4. $3\sqrt{2} + \sqrt{6}$
  5. $6\sqrt{2} - \sqrt{3}$