1-Circumference is equal to the diameter times pi. The diameter is twice the radius. So r=9 then d=18. 18 times pi is 56.55 or 18pi.
2-23pi
3-16 times 2 is 32. so 32pi is your answer.
1- C=20.5 the diameter would be C/pi so 20.5/pi = 6.53 so the radius would be 3.265.
1-203.08
2-1.97 (these are the same as the one above)
1-it would be 69 inches
