Radians & Degrees

This math always come back to me after a certain of time and take me 5 – 10 minutes to think or look around the correct one. So I write this down for myself and others for save time to look around.

radians = degrees * Math.PI / 180
degrees = radians * 180 / Math.PI

P.S.
360 degrees = 2 * Math.PI (radian)