Question

In circle r is the distance between centre and circumference of circle.Then how we can imagine for r^2 and r^3 in terms of imagination as it is in solid angle 's fomula .Also tell how we can imagine solid angle of value such as 270? etc.

Answer 1

Here in case of solid angle, r is the distance between center of front surface and vertex/point at which solid angle is considered. solid angle is not measured in degrees, it is always measured in steradian. To get idea of solid angle , remember its value for sphere and then compare.