Similar shapes and scale factors
Learn Similar shapes and scale factors for Years 9–11 pupils (ages 13–16). Free practice questions, lessons and worked examples — aligned to the UK National Curriculum.
What you'll learn
- 1
Similar shapes have the same angles and their sides are all in the same ratio — the scale factor.
- 2
To find the scale factor, divide a side on the larger shape by the matching side on the smaller.
- 3
Two similar triangles have matching sides 4 cm and 12 cm. What is the scale factor?
- 4
Area does NOT scale by the same factor. If lengths scale by k, areas scale by k² and volumes by k³.
- 5
Two similar solids have lengths in ratio 1:3. Their areas are in ratio 1:9 and their volumes in ratio 1:27.
- 6
Lengths scale by 2. What happens to the area?
- 7
A shape is enlarged by scale factor 5. Its volume becomes how many times bigger?
Practise Similar shapes and scale factors with Whizlo
Free AI-tutored lessons, unlimited practice questions, and progress tracking for ages 13–16. Aligned to the UK National Curriculum.