Question 378091
If the circumference is {{{8*pi}}}, then {{{C = 2*pi * r = 8*pi}}}, or r = 4, the radius.  The equation of the circle is then {{{r^2 = (x-h)^2 + (y-k)^2}}}, or  {{{(x - -3)^2 + (y - 5)^2 = 4^2}}}, or {{{(x + 3)^2 + (y - 5)^2 = 16}}}.