One degree is equal 0.01745329252 radians:
1° = π/180° = 0.005555556π = 0.01745329252 rad
The angle α in radians is equal to the angle α in degrees times pi constant divided by 180 degrees:
α(radians) = α(degrees) × π / 180°
or
radians = degrees × π / 180°
Example
Convert 30 degrees angle to radians:
α(radians) = α(degrees) × π / 180° = 30° × 3.1459 / 180° = 0.5236 rad
Degrees to radians in terms of pi
The angle α in radians is equal to the angle α in degrees times pi constant divided by 180 degrees:
α(radians) = (α(degrees) / 180°) × π
Example
Convert 30 degrees angle to radians in terms of pi:
α(radians) = (α(degrees) / 180°) × π = (30° / 180°) × π
= (1/6) × π = π/6 rad = 0.166667π rad