Circles C1 and C2 , of radii r and R respectively, touch each other as shown in the figure. The line A, which is parallel to the line joining the centres of C1 and C2 , is tangent to C1 at P and intersects C2 at A,B. If R2=2r2, then ∠AOB equals

Circles C1 and C2 , of radii r and R respectively, touch each other as

1.	Circles C1 and C2 , of radii r and R respectively, touch each other as shown in the figure. The line A, which is parallel to the line joining the centres of C1 and C2 , is tangent to C1 at P and intersects C2 at A,B. If R2=2r2, then ∠AOB equals
Answer» Circles $C_{1}$ and $C_{2}$ , of radii $r$ and $R$ respectively, touch each other as shown in the figure. The line $A$ , which is parallel to the line joining the centres of $C_{1}$ and $C_{2}$ , is tangent to $C_{1}$ at $P$ and intersects $C_{2}$ at $A, B$ . If $R^{2} = 2 r^{2}$ , then $∠ A O B$ equals