A) C=3.14 x radius x 2 or C= 3.14 x diameter C= 3.14 x 7 ( because diameter is already given) C = 21.98 B) 3.14 x 9 x 2 ( r is given ) C= 28.26 x 2 C= 56.52 C) 3.14 x 5 x 2 ( r is given ) C= 31.4
The factors for 5 are going to be 1 and 5 or their negative counterparts, since no other whole number within the range of 5 can be multiplied to get 5.