Hello from MrBillDoesMath!
Answer:
7 Pi
Discussion:
If a circle has diameter 14, then
(1/2) C = (1/2) (2 PI* r) as C = 2 Pi * r and 2r = D
= (1/2) (D* Pi)
where C is the circumference, R is the radius of the circle, and D the diameter. IN our case this becomes
(1/2) C = (1/2) (14) * Pi
= 7 Pi
Thank you,
MrB