Answer:
21.99115 ≈ 22 cm
Explanation:
1) So basically in the problem, they give you 7 cm as the diameter.
2) The circumference formula is C = 2πr (if they give you a radius) or C = πd (In this case, this would be the formula to use.)
3) Plug in; C = π(7) = 21.99114858 ≈ 22 cm