Well first you have to find the radius of the circle which is half of the diameter. So 28 divided by 2, so the radius is 14in. Now just plug into the formula and solve for C. C=2[tex] \pi [/tex] times 14
the circumference of a circle can be determined throught the formula C = 2πr where pi is a constant and r is equal to the half of the diameter. the formula hence can be rewritten into C = pi D where d is the diameter. The circumference hence is equal to 28 pi inches
