Does something 2D only be found on a surface of an object, like a drawing?

Question

some thing being 3dimensional has to have an apparent hight and distance of some sort, shadows and dark light have a role in something being 3dimensional as well right, aww d**n it, i'm losing my train of thought, i'm starting to confuse myself

Answer 1

if you really want to freak yourself out go to youtube and look into quantum physics - very cool you will learn about dimensions you never knew existed - but they are actually still there/here - whatever you know what i mean!  but very cool   way better than the physics i dropped in high school!!!

Answer 2

yes...think of it like a triangle shape is 2d and a pyramid is 3d...same basic shape but one is flat and the other has height, depth & width.