MA27-04 Maths Coming soon
Circle theorem: angles in the same segment
MA27-04
This lesson is coming soon.
In this lesson
Prove and use the circle theorem that angles in the same segment, subtended by the same arc, are equal, giving the full correct wording of the reason rather than just its name.
What it covers
- Angles in the same segment, subtended by the same arc, are equal
- Checking two angles genuinely share both the same arc AND the same side (segment) before declaring them equal
- Giving the full statement of the theorem as the reason, not just its name
Key words
For: OCR GCSE J560, Edexcel IGCSE 4MA1, AQA GCSE 8300, Edexcel GCSE 1MA1, Eduqas GCSE C300, Cambridge IGCSE 0580
On the specification
| Board | Spec | Statement |
|---|---|---|
| OCR GCSE J560 | 8.05d | Apply and prove: two angles in the same segment are equal. |
| Edexcel IGCSE 4MA1 | H4.6C | Understand and use angle properties of the circle including: (i) angle subtended by an arc at the centre of a circle is twice the angle subtended at any point on the remaining part of the circumference (ii) angle subtended at the circumference by a diameter is a right angle (iii) angles in the same segment are equal (iv) the sum of the opposite angles of a cyclic quadrilateral is 180° (v) the alternate segment theorem |
| 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 | E4.7 | Circle theorems I |
For teachers
This GCSE Maths lesson teaches circle theorem: angles in the same segment. By the end, students should be able to prove and use the circle theorem that angles in the same segment, subtended by the same arc, are equal, giving the full correct wording of the reason rather than just its name. It works through two worked examples and the mistakes examiners report.