The formula for the circumference of a circle is:
C = 2πr
In this case we know what the circumference (C) is so we can plug that in like so...
75.36 = 2πr
To solve for r you can divide both 2 and π to both sides like so...
75.36 ÷ 2π = (2πr) ÷ 2π
11.9939 = r
r ≈ 12 yards
The radius (r) is half of the diameter, so to find diameter just multiply radius by two...
12 * 2 = 24
The diameter is 24 yards
Hope this helped!
~Just a girl in love with Shawn Mendes