Calculation with cos(angle deg|弧度):
| x (度)  | 
         x (弧度)  | 
         cos x | 
|---|---|---|
| 180° | π | -1 | 
| 150° | 5π/6 | -span style="text-decoration: overline">3/2 | 
| 135° | 3π/4 | -span style="text-decoration: overline">2/2 | 
| 120° | 2π/3 | -1/2 | 
| 90° | π/2 | 0 | 
| 60° | π/3 | 1/2 | 
| 45° | π/4 | span style="text-decoration: overline">2/2 | 
| 30° | π/6 | span style="text-decoration: overline">3/2 | 
| 0° | 0 | 1 |