circumference= 2(pi)r OR (pi)d
d is diameter and r is radius
if the circumference is given, then you would have to work backwards.
in this case, Circumference = 78.5 ft
the equal you would use for the radius would be 78.5 = 2 x 3.14(pi) x r
- multiply 2 x 3.14 and get 6.28
- divide 6.28 on both sides to get ‘r’ by itself
- 12.5 = r
next, for the diameter you can use C= (pi) x d
- 78.5 = 3.14 x D
- divide 3.14 on both sides to get ‘d’ by itself
- 25 = d
hope this helps! make brainliest please