**What is enlargement?**

The word enlargement is usually taken to mean making something bigger.

In Maths, however, it actually means changing the size of an object. It can mean making a shape bigger or making a shape smaller.

**What do we need to have to enlarge a ****shape.**

To enlarge a shape, we need to have a Scale Factor (SF). This tells us how many times bigger the shape is.

A SF of 2 means each side of the shape is twice as big

A SFof 3 means each side of the shape is three times as big.

A SF of 1/2 means each side of the shape is half as long.

**Example 1:**

A shape is enlarged by a SF of 3. If one of the sides in the original shape is 2cm long, how long will it be in the enlarged shape?

All we have to do here is to multiply by 3.

2 cm x 3 = 6 cm

**Example 2: Shape A is enlarged to shape B. What is the scale factor?**

Firstly, we need to say if the enlarged shape is bigger or smaller. As it is bigger, the SF will be a number greater than 1.

All we have to do here is to look at a pair of sides, it doesn't matter which ones as they will all give the same answer.

If we look at the left hand line in each shape, it is 3cm in shape A and 6cm in shape B. This means the SF = 2

**Example 3: Shape B is enlarged to shape A. What is the scale factor?**

Firstly, we need to say if the enlarged shape is bigger or smaller. As it is smaller, the SF will be a number between 0 and 1.

All we have to do here is to look at a pair of sides, it doesn't matter which ones as they will all give the same answer.

If we look at the left hand line in each shape, it is 3cm in shape A and 6cm in shape B. This means the SF = 1/2