Try to learn this values, at least the sine and cosine ones, because they will be very useful when you won’t have a calculator.
| $\alpha$ | $\alpha$ (Radians) | $\sin\alpha$ | $\cos\alpha$ | $\tan\alpha \space [=\frac{\sin\alpha}{\cos\alpha}]$ |
|---|---|---|---|---|
| 0° | 0 | 0 | 1 | 0 |
| 30° | $\frac{\pi}{6}$ | $\frac{1}{2}$ | $\frac{\sqrt{3}}{2}$ | $\frac{\sqrt{3}}{3}$ |
| 45° | $\frac{\pi}{4}$ | $\frac{\sqrt{2}}{2}$ | $\frac{\sqrt{2}}{2}$ | 1 |
| 60° | $\frac{\pi}{3}$ | $\frac{\sqrt{3}}{2}$ | $\frac{1}{2}$ | $\sqrt{3}$ |
| 90° | $\frac{\pi}{2}$ | 1 | 0 | DOES NOT EXIST |
Magic trick below ⬇️
https://www.youtube.com/watch?v=jI81WXyFrL0
Here are some important associations between different angles.