If the diameter is 121/2 what is the circumference

Question

12 "1/2" In diameter using 22/7 as pie. What is the circumference

Answer 1

Whoever told you to use 22/7 as pi

is definitely not interested in

accuracy.  However;

 

c = 2(pi)r = pi(d)

 

c = (22/7)(25/2)

c = [22(25)/[7(2)]

c = 11(25)/7

c = 275/7

c = 39 2/7

Answer 2

C = 2(pi)(radius) = (2)(pi)(12.5)/2 using r = half of diam, diam = 12.5"

Revised due to confused expressions given for diameter; thank you for pointing that out, Andrew.