The radian is the only angle unit used by " true " mathematicians.

Degrees, minutes, ........... is not a unit but results from a convention very useful long time ago and in the physical world so switchmen, astronomy...

Never the less the radian is in fact the only true angle unit :

Of course, preferably used in multiples or fraction of " ".

An angle in radians is the length of the arc of a circle divided by the radius :

For any whole circle (so the total of the arc) we get as the perimeter is .

Then the angle is for the total length of the arc.

Therefore, i prefer to measure angles using  radians. \ \

I prefer to measure angles using  radians.