Two ways to measure an angle
| Mode | Full turn | Typical notation |
|---|---|---|
| Degrees | 360° | 30°, 45°, 90° |
| Radians | 2π | π/6, π/4, π/2 |
Worked comparison
sin(30°) = 0.5
In DEG mode, enter sin(30). In RAD mode, the same input means 30 radians and gives a very different result.
- Look for a degree symbol or π in the problem.
- Choose DEG or RAD in the calculator header.
- Enter the trigonometric function and angle.
- For inverse trig, remember that the output follows the selected angle mode.
Equivalent angles
30° = π/6 radians
Therefore sin(30) in DEG mode and sin(pi/6) in RAD mode both equal 0.5.
Practice
Find cos(π/3).
Show answer
Select RAD and enter cos(pi/3). The answer is 0.5.
Try the method now
Open the calculator in a separate tab and reproduce the worked example.
Related guides
Reviewed July 17, 2026.