New
New
Year 7

# Enlarging objects

I can enlarge objects using information about the centre of enlargement and scale factor

New
New
Year 7

# Enlarging objects

I can enlarge objects using information about the centre of enlargement and scale factor

## Lesson details

### Key learning points

1. Each length in the shape is multiplied by the scale factor
2. Each vertex in the object is a given distance from the centre of enlargement
3. This distance is also multiplied by the scale factor to give the distance of the image's vertex

### Common misconception

Pupils may initially be unsure when enlarging shapes on different background in Q2 of Task B.

Stress that they can use the same methods as for square or plain backgrounds (e.g. using a ruler, counting units along gridlines).

### Keywords

• Centre of enlargement - The centre of enlargement is the point from which a shape is enlarged.

• Scale factor - A scale factor is the multiplier between similar shapes that describes how large one shape is compared to the other.

During the second cycle, the examples only use one method to perform the enlargements. Stress that any of the methods from the first cycle could be used to enlarge the shapes.
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.
Scale factor is the between similar shapes that describes how large one shape is compared to the other.
Q2.
The invariant point from which an object is enlarged is known as the _________________.
Correct Answer: centre of enlargement, Centre of enlargement
Q3.
P has been enlarged to create A. What is the scale factor?
$$1\over2$$
8
16
Q4.
P has been enlarged to create A. What is the value of $$a$$?
3
4
12
Correct answer: $$1\over2$$