randFromArray(commonAngles)

Convert the angle ANGLE.deg° to radians.

ANGLE.deg / 180 * PI radians

There are `360` degrees in a circle. There are also `2\pi` radians in a circle.

In other words, there are `\pi` radians per `180` degrees. So we can convert from degrees to radians by multiplying by `\pi`, and dividing by `180^\circ`.

`ANGLE.deg^\circ \times \dfrac{\pi}{180^\circ}`

`\displaystyle = ANGLE.rad` radians