Answer:
5 x 2 x 3.14 = 31.4
Formula of circumference:
radius(half of your diameter or given radius) x pi(3.14 or 22/7 depending on what they tell you to use for pi) x 2(just always there when finding circumference)
I think the GCF is 4x in not sure olz tell me if i'm wrong
Exact Form:
√15/4 -1/3
Decimal Form:
0.63491250