A square has 2 dimensions: length and width.

2D or two-dimensional objects have two measurements: width and length, like a square. 2D objects do not have depth, like 3D objects.

The simplest 2D shape is a triangle. A 2D object can have any number of sides, making shapes such as pentagons and hexagons. The sides can bend to make different angles. 2D objects can even have sides that go through each other.

Two dimensional space is a mathematics tool, and it has many kinds of uses in computer science, geometry, the making of software, and also in paper.