3d.
Chat with our AI personalities
A piece of paper is 3D.
2d
A line (2D), ray (2D), vector (2D), line segment (2D), a mobius strip (3D), or a klein bottle (3D).
A television set is a 3D shape. The image (picture) on the television screen is a 2D shape. 3D is when it has length, width, and height. 2D is only length and width.
The suffix "hedron" implies 3D. The 2D suffix is "gon"