Chat with our AI personalities
A steradian is the solid angle subtended at the centre of a sphere by radius r by a portion of the surface of the sphere which has area r2.
A solid angle, measured from a vertex, is the ratio between the area subtended by the angle at the vertex and the the square of the distance to the vertex. The unit of measurement is the stradian.
an angle subtended by an arc is double at the center
It will be the same angle subtended by its circumference.
An angle subtended at the semicircular arc is 90 degrees.