Two dimensional (2D) shapes are flat.

2D shapes have sides and angles. (Curved shapes don't have angles.)

Circles and ovals are curved shapes.

A polygon has straight sides and angles.

What else do you know about polygons?

A three-dimensional (3D) shape is a solid figure or object.

3D shapes have faces, edges and vertices (singular: vertex).

A face is a single flat surface.

An edge is the line where the faces meet.

A vertex (plural: vertices) is a corner.

What else to you know about three-dimensional figures?