# Recognise and describe 2D shapes

## Learning focus

Learn to recognise 2D shapes based on their properties.

This includes:

- one quiz
- a learning summary
- two videos
- one interactive activity

# Quiz

Test your knowledge of recognising 2D shapes in this quiz.

# Learn

Let's start this lesson with a fun video all about 2D shapes from KS2 Maths.

## What are 2D shapes?

2D shapes are everywhere!

For example, windows are usually shaped like rectangles and clocks are shaped like circles.

2D shapes are flat and all have different properties.

## Properties

A **property** is a quality that a shape has. Examples of shape properties are:

- number of sides
- number of angles (corners)
- length of sides
- types of angles (acute, obtuse, right-angle)
- perpendicular and parallel lines

Take a look at these shapes and their properties:

## Triangles

All triangles have 3 sides and 3 angles.

However, different triangles have different properties, depending on how they are drawn. You have to look very carefully to see what is different.

For example, compare these two triangles:

Like all triangles, both have 3 sides and 3 angles.

However, the yellow triangle’s sides are all the **same length** and the angles are all the **same size**.

The green triangle has a **right-angle** and all the sides are a **different length**.

## Quadrilaterals

A quadrilateral is a shape with 4 sides and 4 angles.

These are some examples of quadrilaterals and their properties:

### Square

Sides all equal length.

Angles all right-angles (perpendicular lines).

2 pairs of parallel lines.

### Rectangle

2 sides longer than the others.

Angles all right-angles (perpendicular lines).

2 pairs of parallel lines.

### Trapezium

1 pair of parallel lines.

2 sets of equal angles.

2 lines equal length and 2 that aren’t.

### Kite

2 pairs of equal sides.

1 pair of equal angles.

No parallel lines.

## Regular polygons

These are shapes that have all equal sides and equal angles.

### Pentagon

- 5 equal sides and angles.

### Hexagon

6 equal sides and angles.

3 pairs of parallel lines.

### Heptagon

- 7 equal sides and angles.

### Octagon

8 equal sides and angles.

4 pairs of parallel lines.

## Irregular polygons

These are shapes that have sides and angles of **different sizes**.

You can always identify the polygon by how many sides it has, e.g. a pentagon is always a shape that has 5 sides.

### Example:

This irregular pentagon has sides and angles that are different lengths and sizes.

It has two right angles and one pair of equal sides. The other 3 sides are different lengths.

It's party time! Let's recap how to identify different types of polygons with this video from KS2 Maths.

# Practise

Try this interactive activity. Can you identify the 2D shape from the description?

# Play

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

# There's more to learn

Have a look at these other resources.