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MA26-08 Maths Coming soon

Proving results using similarity and Pythagoras

MA26-08

This lesson is coming soon.

In this lesson

Chain similarity reasoning with Pythagoras' theorem to derive and prove a geometric result.

What it covers

  • Combining a similarity argument with Pythagoras' theorem to derive and prove a result
  • Modelling the full multi-step argument through to its numeric or algebraic conclusion
  • Checking a right angle is actually given or justified before applying Pythagoras, rather than assuming one from the diagram's appearance

Key words

For: AQA GCSE 8300, Edexcel GCSE 1MA1, Eduqas GCSE C300, OCR GCSE J560

On the specification

BoardSpecStatement
AQA GCSE 8300G6Apply angle facts, triangle congruence, similarity and properties of quadrilaterals to conjecture and derive results about angles and sides, including Pythagoras’ theorem and the fact that the base angles of an isosceles triangle are equal, and use known results to obtain simple proofs
Edexcel GCSE 1MA1G6Apply angle facts, triangle congruence, similarity and properties of quadrilaterals to conjecture and derive results about angles and sides, including Pythagoras’ theorem and the fact that the base angles of an isosceles triangle are equal, and use known results to obtain simple proofs
Eduqas GCSE C300FG6Apply angle facts, triangle congruence, similarity and properties of quadrilaterals to conjecture and derive results about angles and sides, including Pythagoras' Theorem and the fact that the base angles of an isosceles triangle are equal, and use known results to obtain simple proofs
Eduqas GCSE C300HG6Apply angle facts, triangle congruence, similarity and properties of quadrilaterals to conjecture and derive results about angles and sides, including Pythagoras' Theorem and the fact that the base angles of an isosceles triangle are equal, and use known results to obtain simple proofs
OCR GCSE J5609.02bApply congruent triangles in calculations and simple proofs.
For teachers

This GCSE Maths lesson teaches proving results using similarity and Pythagoras. By the end, students should be able to chain similarity reasoning with Pythagoras' theorem to derive and prove a geometric result. It works through two worked examples and the mistakes examiners report.