Our formula is:
[tex](x-2)^2 + (y-3)^2 = 16[/tex]
Which is in the general formula for a circle:
[tex](x-a)^2 + (y-b)^2 = r^2[/tex]
Where (a,b) is the coordinate for the center of our circle and r^2 is the radius squared.
Therefore, the center of our circle is at (2,3) and the radius is √16 = 4.