2D Shapes - Terminology

There are some words and symbols that are used when describing shapes that your child needs to know to be able to work with 2D and 3D shapes.



Lines that are the same distance apart along their length are said to be parallel. They do not have to be the same length and can even be curved. They just have to be the same distance apart and never meet - like a railway track.

When lines are parallel we use the > (or >> if there are two sets) to show that the lines with this symbol on them are parallel to each other.



Right Angle / Perpendicular

This symbol  Data  shows that the angle is 90° or a Right Angle

It two lines are at 90° to each other, they are said to be perpendicular


Line CB is at right angles to Line BD      Line CB is perpendicular to Line AD


Lines of Same Length

You will often see these symbols on a pair of lines.

It means they they are the same length.


Vertex / Vertices

A corner or point in between two sides of a shape which form an angle is known as a Vertex. The plural of Vertex is Vertices.

A triangle has three vertices and a square has four vertices.

CAT4 / 12 Pus papers