Question

Let AB be the diameter of circle Γ1. In the interior of Γ1, there are circles Γ2 and Γ3 that are tangent to Γ1 at A and B, respectively. Γ2 and Γ3 are also externally tangent at the point C. This tangent line (at C) cuts Γ1 at P and Q, with PQ=20. The area that is within Γ1 but not in Γ2 or Γ3 is equal to Mπ. Determine M