What is the relationship between radian and steradian?

Answer by  Dan3686 (969)

The steradian is related to the radius of a sphere. Imagine the cross section of a pie (or circle) then this is the radius or radian. The steradian is the same but for a sphere.

Answer by  catysuzgirl2000 (578)

In mathematics, a steradian is a 'solid angle' that 'cuts out' an area of a sphere in a three dimensional medium, whereas the radian is a flat angle that "cuts out" an arc or a length of a circle's circumference.

Answer by  KenHill (8)

A radian is like a "slice of pie" in a circle. A steradian is a "three-dimensional" slice of pie; that is, it is a "slice" out of a sphere, rather than a "slice" out of a two-dimensional circle. In short, a steradian is a three-dimensional radian.

Answer by  EramNazir (6)

Both the Radian and steradian are regarded as SI base unit. They serve as the supplementary unit, leaving open the question of whether plane angle or solid angle.

Answer by  Gabriel (2146)

A radian measures an angle on a two dimensional plane. The steradian measures an angle on three dimension. What the radian measures on a circle, the steradian would measure in a sphere.

Answer by  lilian (397)

A steradian measures "solid" angles and is related to the surface area of a sphere. The radian is related to the circumference of a circle. The seradian is used in two-dimensional angular spans in three-dimensional space, while the radian is used for angles in a plane. Steradian comes from Greek for solid and radius comes from Latin for ray.

Answer by  aurynbearer (110)

In a two-dimensional universe, the angle, as measured in radians, equals the arc length divided by the radius of the circle. Similarly, in a three-dimensional space, the angle in steradians equals the area (surface) it cuts divided by the squared radius of the sphere.