New
New
Year 7

# Introduction to enlargements

I can understand the nature of enlargements and appreciate what changes and what is invariant

New
New
Year 7

# Introduction to enlargements

I can understand the nature of enlargements and appreciate what changes and what is invariant

## Lesson details

### Key learning points

1. An enlargement means a change in size.
2. The lengths of the lines may change when enlarged.
3. The angles inside an object do not change when enlarged.
4. When an object is enlarged, the image is similar.

### Common misconception

Enlargement only refers to an increase in size.

The transformation 'enlargement' refers to a change of size that can be either a stretch or a shrink.

### Keywords

• Enlargement - Enlargement is a transformation that causes a change of size.

• Similar - Two shapes are similar if the only difference between them is their size. Their side lengths are in the same proportions.

Pupils will need square paper and scissors to complete question 2 of Task B.
Teacher tip

### Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

## Starter quiz

### 6 Questions

Q1.
The object is what we call a shape after it has been transformed.
True
Q2.
Which property is not invariant when a shape is translated?
side lengths
angles
orientation
Q3.
Which properties are not invariant when a shape is rotated?
side lengths
angles
Q4.
Which properties are not invariant when a shape is reflected?
side lengths
angles
Q5.
Match each number on the left with its multiple on the right. There is only one possible solution.

6

9

16

30

Q6.
Which of these is the correct location of the reflected image of vertex A?
a
b
c

## Exit quiz

### 6 Questions

Q1.
__________ is a transformation that causes a change of size.
Q2.
Two shapes are if the only difference between them is their size.
Q3.
Enlarging a shape means the shape will always get bigger.
True
Q4.
Which property is invariant when a shape is enlarged?
side lengths