${\alpha }^{\circ }$

$\sin \alpha$

$1-\sin \alpha$

$\pi \left[1/\left(1-\sin \alpha \right)-1/3\right]$

30

0.5000

0.5000

0.5236

40

0.642787609

0.35721239

7.7475

50

0.766044443

0.23395556

13.4282

60

0.866025403

0.13397460

23.4492

70

0.93969262

0.06030738

52.0930

80

0.984807753

0.01519225

207.7429

89.5

0.999961923

0.00003808

82,499.8071