MA27-08 Maths Coming soon
Circle theorem: tangents from an external point
MA27-08
This lesson is coming soon.
In this lesson
Prove, using congruent triangles, and use the circle theorem that two tangents drawn from the same external point to a circle are equal in length.
What it covers
- Two tangents drawn from the same external point to a circle are equal in length
- Proving this using congruent triangles (RHS or SAS)
Key words
For: AQA GCSE 8300, Edexcel GCSE 1MA1, Eduqas GCSE C300, Cambridge IGCSE 0580, Edexcel IGCSE 4MA1
On the specification
| Board | Spec | Statement |
|---|---|---|
| AQA GCSE 8300 | G10 | Apply and prove the standard circle theorems concerning angles, radii, tangents and chords, and use them to prove related results |
| Edexcel GCSE 1MA1 | G10 | Apply and prove the standard circle theorems concerning angles, radii, tangents and chords, and use them to prove related results |
| Eduqas GCSE C300 | HG10 | Apply and prove the standard circle theorems concerning angles, radii, tangents and chords, and use them to prove related results |
| Cambridge IGCSE 0580 | C4.8 | Extended content only. |
| Cambridge IGCSE 0580 | E4.8 | Circle theorems II |
| Edexcel IGCSE 4MA1 | F4.6B | Understand chord and tangent properties of circles |
For teachers
This GCSE Maths lesson teaches circle theorem: tangents from an external point. By the end, students should be able to prove, using congruent triangles, and use the circle theorem that two tangents drawn from the same external point to a circle are equal in length. It works through two worked examples and the mistakes examiners report.