Theory:

Shadow play
Shadow play is one of the ways of viewing solids. When light falls on an object, the resultant shadow thus formed is two-dimensional.
 
The two-dimensional figures projected as shadows depends on the solids placed under the lights.
Example:
When light is placed adjacent to a sphere, the shadow thus formed is circular.
 
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Important!
What happens with the changing position of the sun?
 
Sunlight is the natural light source, which can be used to perform the experiment mentioned above, but the orientation of the images will vary based on the position of the sun.
 
That is, we all know that the sun rises in the east and sets in the west. The position of the sun keeps varying throughout the day. Therefore, the size and direction of the shadow thus formed will also differ based on the position of the sun.