Respuesta :

Answer:

x^2 + y^2 = 400

Step-by-step explanation:

The equation for a circle is

(x-h)^2 + (y-k)^2 = r^2

where (h,k) is the center and r is the radius

(x-0)^2 + (y-0)^2 = 20^2

x^2 + y^2 = 400