Question

What is the solid angle formula?

Answer 1

Solid angle:

The solid angle($\Omega$) is the ratio of the area of the part of the spherical surface subtended and the radius of the area of the part of the spherical surface subtended.

Mathematically it can be written as:

$\Omega =\frac{A}{r^2}$

The solid angle is represented by a symbol $\Omega$ and it's S.I unit is steradian.