Full name: radian
Plural form: radians
Symbol: rad
Alternate spelling: c
Category type: angle
Scale factor: 1
The SI derived unit for angle is the radian.
Valid units must be of the angle type.
You can use this form to select from known units:
In mathematics and physics, the radian is a unit of angle measure. It is the SI derived unit of angle. It is defined as the angle subtended at the center of a circle by an arc of circumference equal in length to the radius of the circle. Angle measures in radians are often given without any explicit unit. When a unit is given, sometimes the abbreviation rad is used, sometimes the symbol c (for "circular").