Explanation:
The center of the circle is at (2,2), so we know its equation is (x-2)^2 + (y-2)^2 = r^2.
To find r, we can find the distance between the center, (2,2), to one of the points on the circumference. One of these points is (-1,2), meaning the radius is 3.
So, the equation is (x-2)^2 + (y-2)^2 = 9.