Degrees and radians, both ways

You will write two small functions that change the unit of an angle, and use one of them to write angles as multiples of $\pi$.

The idea. $\pi$ rad $= 180^\circ$. So multiply by $\frac{\pi}{180}$ for radians, and by $\frac{180}{\pi}$ for degrees. An angle of $d$ degrees is $\frac{d}{180}$ of $\pi$.

Your tasks.

1. Finish to_radians(deg).
2. Finish to_degrees(rad).
3. Fill the list multiples with each angle of angles as a multiple of $\pi$. For $90^\circ$ it would be $0.5$.