The standard form of a circle is (x - h)² + (y - k)² = r² where (h, k) is the center point and r is the radius. In this case, the center is the origin which has coordinates of (0, 0) so h = 0 and k = 0. We know that the radius is 5 so r = 5. Therefore, after plugging in the values of h, k, and r, we get that the answer is x² + y² = 25.
