Angle of Intersection of Two Circles

Q.

The angle at which the circles $(x-1{)}^2+y^2=10and{x}^2+(y-2{)}^2=5$ intersect is

1. $\frac{\pi }{6}$

2. $\frac{\pi }{4}$

3. $\frac{\pi }{3}$

4. $\frac{\pi }{2}$

Q. The angle between the circles $S_1:x^2+y^2-4x+6y+11=0$ and $S_2:x^2+y^2-2x+8y+13=0$ is

1. ${90}^{\text{o}}$
2. ${60}^{\text{o}}$
3. ${45}^{\text{o}}$
4. ${30}^{\text{o}}$