MA26-12 Maths Coming soon
Similar shapes: persisting the relationship across a question
MA26-12
This lesson is coming soon.
In this lesson
Recognise when a later part of a question still needs a similarity relationship established earlier, and use it to find a further unknown length.
What it covers
- Recognising that a later part of a multi-part question still needs the similarity (or congruence) relationship established in an earlier part
- Checking a scale factor derived from one pair of corresponding sides is consistent, rather than assuming it without verifying
- Using a persisted similarity relationship to find a further unknown length in a later part of the same question
Key words
For: AQA GCSE 8300, Edexcel GCSE 1MA1, Eduqas GCSE C300
On the specification
| Board | Spec | Statement |
|---|---|---|
| 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 | FG17 | Apply the concepts of congruence and similarity, including the relationships between lengths 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 similar shapes: persisting the relationship across a question. By the end, students should be able to recognise when a later part of a question still needs a similarity relationship established earlier, and use it to find a further unknown length. It works through two worked examples and the mistakes examiners report.