The equation of circle is: (x-a)^2+(y-b)^2=r^2 where C(a, b) is the center. In order to find r you have to find the distance between C(-2, 1) and let's say A(-4, 1)
The formula for distance is:
r = 2
The equation of circle is (x+2)^2+(y-1)^2=4
I hope that this is the answer that you were looking for and it has helped you.