Answer:
x^2+y^2=6^2
Explanation:
The equation of a circle is (x-h)^2+(y-k)^2=r^2
where h is the x coordinate of the center, k is the y coordinate of the center, and r is the radius of the circle.
We can see the center is on 0,0, and the radius is 6, so our equation is
(x-0)^2+(y-0)^2=6^2
or
x^2+y^2=6^2