# 9.05 Enlargements

Lesson

## Ideas

Do you know how a  translation, reflection or rotation  changes the position of a shape or object?

### Examples

#### Example 1

Choose the picture that shows a reflection.

A
B
C
Worked Solution
Create a strategy

Choose the option that shows two objects that are mirror-images of each other.

Apply the idea

Option C is the correct answer because the two kangaroos are mirror-images of each other.

Idea summary

Translations, reflections and rotations change the position or orientation of the shape, but the shape itself stays the same.

## Enlargement

An enlargement is another way to transform a shape or object. Let's learn more about them now.

### Examples

#### Example 2

The right rectangle is an enlargement of the left rectangle.

a

What is the enlargement factor?

Worked Solution
Create a strategy

Divide the large rectangle's length by the small rectangle's length.

Apply the idea
b

Write the scale of the small rectangle to the large rectangle.

Worked Solution
Create a strategy

Use the fact from part (a) that large rectangle is 3 times as large as the small rectangle.

Apply the idea

We can say that every 1 cm on the small rectangle is 3 cm on the large rectangle.

This means that the scale of the small rectangle to the large rectangle is given by:1:3

Idea summary

An enlargement keeps the same shape but changes the size of it.

### Outcomes

#### VCMMG201

Apply the enlargement transformation to familiar two dimensional shapes and explore the properties of the resulting image compared with the original