MA26-05 Maths Coming soon
Area ratio of similar shapes
MA26-05
This lesson is coming soon.
In this lesson
Use the square of the linear scale factor to find an unknown area in similar shapes.
What it covers
- Area scale factor = (linear scale factor) squared
- Applying the area scale factor to find an unknown area, or to work backwards to a linear scale factor from a given area ratio
- Multi-step problems where the area ratio feeds into a further proportion (e.g. a shaded-region fraction)
Key words
For: Cambridge IGCSE 0580, Edexcel IGCSE 4MA1, OCR GCSE J560, AQA GCSE 8300, Edexcel GCSE 1MA1, Eduqas GCSE C300
On the specification
| Board | Spec | Statement |
|---|---|---|
| Cambridge IGCSE 0580 | E4.4 | Calculate lengths of similar shapes. |
| Edexcel IGCSE 4MA1 | H4.11A | Understand that areas of similar figures are in the ratio of the square of corresponding sides |
| Edexcel IGCSE 4MA1 | H4.11B | Understand that volumes of similar figures are in the ratio of the cube of corresponding sides |
| Edexcel IGCSE 4MA1 | H4.11C | Use areas and volumes of similar figures in solving problems |
| OCR GCSE J560 | 9.04c | Compare lengths, areas and volumes using ratio notation and scale factors. |
| AQA GCSE 8300 | G19 | Apply the concepts of congruence and similarity, including the relationships between lengths in similar figures |
| AQA GCSE 8300 | R12 | Compare lengths, areas and volumes using ratio notation |
| Edexcel GCSE 1MA1 | G19 | Apply the concepts of congruence and similarity, including the relationships between lengths, in similar figures |
| Edexcel GCSE 1MA1 | R12 | Compare lengths, areas and volumes using ratio notation; make links to similarity (including trigonometric ratios) and scale factors |
| Eduqas GCSE C300 | HG19 | Apply the concepts of congruence and similarity, including the relationships between lengths, areas and volumes in similar figures |
| Eduqas GCSE C300 | FR13 | Compare lengths, areas and volumes using ratio notation; make links to similarity (including trigonometric ratios) and scale factors |
| Eduqas GCSE C300 | HR13 | Compare lengths, areas and volumes using ratio notation; make links to similarity (including trigonometric ratios) and scale factors |
For teachers
This GCSE Maths lesson teaches area ratio of similar shapes. By the end, students should be able to use the square of the linear scale factor to find an unknown area in similar shapes. It works through two worked examples and the mistakes examiners report.