# Recognise 2D and 3D shapes

## Learning focus

Learn how to recognise 2D and 3D shapes from descriptions of their properties.

This lesson includes:

- one catch-up quiz
- one learning summary

# Quiz

To get started, let's see how well you know this topic already. Take the catch-up quiz below to find out.

# Learn

**2D shapes** can be described by their sides, their angles and their symmetry.

The sides might be equal in length and some might be parallel.

The angles could be right angles, but sometimes they are greater than or less than a right angle.

A 2D shape could have line symmetry or rotation symmetry, or both!

**3D shapes** are described by their faces, edges and vertices.

The faces can be the same shape or different, and a 3D shape could have a curved surface as well as flat faces.

## Example 1

Dawn describes a 2D shape as having 4 right angles. What shape could it be?

A square has 4 right angles and 4 equal sides.

A rectangle has 4 right angles, but not equal sides.

Dawn’s shape could be a square or a rectangle.

## Example 2

Bruce draws this quadrilateral. How can we describe it?

- It has 4 equal sides, and the opposite sides are parallel.
- It has 4 angles but none are right angles.
- The opposite angles are equal.

It is a rhombus.

## Example 3

Sophie draws this triangle. How can we describe it?

- It has 3 sides that are all different lengths.
- It has 1 right angle.

It is a right-angled scalene triangle.

## Example 4

Mika draws a shape with 5 equal sides and 5 equal angles. What is her shape?

A shape with 5 equal sides and 5 equal angles is a pentagon.

## Example 5

Chloe notices that her 3D shape has 5 flat faces. 4 of the faces are triangles.

She also counts that it has 8 edges and 5 vertices. What is her shape?

Chloe’s shape is a square-based pyramid.

# Play

Play **Guardians: Defenders of Mathematica** to learn more about this topic and test your skills.

# There's more to learn

Have a look at these other resources.