Answer:
c = 2 * 3.14 * r and c = 3.14 * d
Step-by-step explanation:
The formulas for the circumference of a circle are
c = 2πr and c = πd
where r is the radius and d is the diameter
using π = 3.14
the formulas become
c = 2 * 3.14 * r and c = 3.14 * d