Question

what is shadow and how is it formed form

Answer 1

Shadow:
A shadow is a dark area where light from a light source is blocked by an opaque object. It occupies all of the three-dimensional volume behind an object with light in front of it.

Shadows are formed by light, because if light shines onto an object, and the object blocks the light, the light will go sideways of the object, and therefore, a shadow is formed. ... Most shadowsare made up of the umbra and the penumbra. All light is blocked by an opaque object in the umbra.