From Simple English Wikipedia, the free encyclopedia
A square has 2 dimensions: length and width.

Any shape that have only two faces are 2D shapes. 2D or two-dimensional objects have two measurements: width and length, like a square. Two-dimensional objects do not have depth, like a cube. It's a mathematics tool, but it's also used in video games, and computer science and also in paper

Throughout maths, it is used in geometry and other categories.