Answer:
Center= (-6,-8)
Radius= 6
Explanation:
We use the formula (x-h)^2+(y-k)^2 then plug in our numbers:

In the equation -h is 6 so our h (x-coordinate) is -6
In the equation -k is 8 so our k (y-coordinate) is -8
In the equation r^2 is 36 so we take the square root of 36 to get r which is 6.