Answer:
The circle is centered at (-8,3) and has a diameter of 20 units
Step-by-step explanation:
we know that
The equation of a circle in center radius form is equal to

where
(h,k) is the center of the circle
r is the radius of the circle
In this problem we have

so
The center is the point (-8,3)
The radius is 
so
The diameter is two times the radius

therefore
The circle is centered at (-8,3) and has a diameter of 20 units