Connection of the radian with other units (minutes and seconds)
An angle of 1 radian
The proportion of the radian and other units of angular measurement is described by the formula:
1 rad = 1/2π turns = 180°/π degrees = 200g/π grads.
Obviously, a flat angle equals 180° or (π·R)/R = π rad.
This suggests a trivial formula of translation from degrees, minutes, and seconds to radians and vice versa.
where α[rad] is an angle measured in radians, and [°] is an angle measured in degrees.