It is centered at (h,k) --> (0,0) and has a radius 9
The equation of the circle is
[tex](x-h)^{2} +(y-k)^{2} =r^{2} \\(x-0)^{2} +(y-0)^{2} =r^{2}\\x^{2} +y^{2} = 9^{2}[/tex]
Hope that helps!
