2D shapes

What are 2D shapes?

Two-dimensional (2D) shapes are completely flat. They cannot be picked up.

2D shapes can be found printed in a book or you can draw them on a piece of paper.

2D shapes have sides and corners (also called vertices).

Here are some 2D shapes you might know.

Quiz: 2D shapes

Why not see how much you know about this topic already? Then work through the page and see if you can beat your score.

Properties of 2D shapes

2D shapes have sides and corners. Another name for a corner is a vertex.

A vertex is a point where two or more lines meet. The plural of vertex is vertices.

The number of sides and vertices are the properties of a shape.

Let’s look at the number of sides and vertices that some 2D shapes have.

Here is a triangle. Can you count the number of sides and vertices?

A triangle has 3 sides and 3 vertices.

Now let’s look at a square.

A square has 4 sides and 4 vertices.

Finally let’s look at a pentagon.

What do you notice about the number of sides and the number of vertices each shape has?

They are the same.

Here is a table to help you remember how to identify some common 2D shapes by their properties.

What is a polygon?

A polygon is a 2D shape with straight sides that meet at vertices.

Polygons have three or more sides.

Have a look at these three shapes. One of them is not a polygon. Can you work out which?

A circle is not a polygon because it doesn’t have straight sides.

Polygons can look quite different, but have the same name.

For example, look at these two shapes and count the sides on each.

Can you see both shapes have 6 sides, so both shapes are hexagons.

What is different about the two shapes?

All the sides on the first shape are the same length. However, the second shape has sides which are different lengths.

Example 1

Look at these shapes and count the sides and vertices.

Example 2

Fatima has drawn a shape. Does it remind you of any other shape?

Example 3

Look at these different shapes.