Okay, well to start with, the equation for the circumference of a circle is C = 2(pi)r, and since we are given the radius (14 7/8ft) we can easily plug it in to this equation.
Now, for simplicity, I am going to put the fraction into decimal form.
14 7/8 = 14.875.
Now, plug it into the equation for circumference.
C = 2(pi)(14.875)
Use a calculator
C = 93.5, or about 93 1/2ft.
The closest estimate is 90ft.