Γ 1 is a circle with center O 1 and radius R 1 , Γ 2 is a circle with center O 2 and radius R 2 , and R 2 <R 1 . Γ 2 has O 1 on its circumference. O 1 O 2 intersect Γ 2 again at A . Circles Γ 1 and Γ 2 intersect at points B an