1) Take the equation of the circumference of a circle ( C = 2*pi*r )
2) Plug in what you have. ( 112 = 2*pi*r )
3) Divide each side by pi*r. ( 112 / 2*pi=r )
4) Solve this equation.. ( You get the radius by multiplying the answer by 2 )
The diameter is 351.86 inches.