Definition of steradian in English:
The SI unit of solid angle, equal to the angle at the centre of a sphere subtended by a part of the surface equal in area to the square of the radius.
- A sphere subtends 4 pi square radians (steradians) about the origin.
- There are also two supplementary units, the radian, and the steradian.
- This is the power of the light that is emitted per projected surface area into a given solid angle, and it is measured in watts per square metre per steradian.
Definition of steradian in:
- US English dictionary