Answer:

1. ans-C≈43.98

SOLUTION:

C=2πr=2·π·7≈43.9823

2.ans-C≈25.13

SOLUTION :

C=2πr=2·π·4≈25.13274

3. ans-C≈75.4

SOLUTION :

C=2πr=2·π·12≈75.39822

4. ans-C≈56.55

SOLUTION:

C=2πr=2·π·9≈56.54867

5. ans-C≈21.99

SOLUTION:

C=2πr=2·π·3.5≈21.99115