Question

Can you think of creating a shape that would be circular shadow if held in one way and a rectangular Shadow when held in another way

Answer 1

it can be a cylinder because when it is held horizontally and the source of light is perpendicularly above it then it forms a rectangular shadow beneath it 

when it is held horizontally and source of light is vertically beside it then it forms a circular shadow on the other side of it.

hope it helps:)