1 π= 3.14

2 π= 6.28

3 π= 9.42

4 π= 12.56

5 π= 15.7

6 π= 18.84

7 π= 21.98

8 π= 25.12

9 π= 28.26

10 π= 31.4

11 π= 34.54

12 π= 37.68

13 π= 40.82

14 π= 43.96

15 π= 47.1

16 π= 50.24

17 π= 53.38

18 π= 56.52

19 π= 59.66

20 π= 62.8