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
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
1兀31.4
2兀6.28
……