Answer: Choice B) multiply the radius by 2, then by 3.14
The formula is
C = 2*pi*r
which you can rearrange to get C = 2*r*pi, showing you multiply 2 and the radius r, then multiply by pi = 3.14 which is approximate
A similar related formula is
C = pi*d
where d is the diameter. Note that d = 2*r, so we can replace d with 2r to get the first formula back again.
the circumference is the distance or perimeter around the circle