The standard form of the equation of a circle is: `(x-h)^2+(y-k)^2` , where the center C is (h,k) and the radius is r.
Here, the given equation is `x^2 + (y-3)^2 = 25` . We can rewrite this equation as:
Therefore, a) the center C is (0,3)
b) the length of the radius r is 5 units.