MA25-03 Maths Coming soon
Angles on parallel lines
MA25-03
This lesson is coming soon.
In this lesson
Identify alternate, corresponding and co-interior (allied) angles on parallel lines by their correct formal name, use them to find missing angles, and only apply them once parallelism is actually established.
What it covers
- Identify the F-shape (corresponding angles, equal), Z-shape (alternate angles, equal) and C/U-shape (co-interior/allied angles, sum to 180 degrees) on a pair of parallel lines cut by a transversal
- Use the correct board-accepted term (alternate angles, corresponding angles, or co-interior/allied angles) as the reason, not an informal shape name like 'Z angles'
- Check that lines are actually marked as parallel (matching arrows) before applying any of these three facts
- Find a missing angle using exactly one of these three relationships
Key words
For: AQA GCSE 8300, Edexcel GCSE 1MA1, Eduqas GCSE C300, Edexcel IGCSE 4MA1, Cambridge IGCSE 0580, OCR GCSE J560
On the specification
| Board | Spec | Statement |
|---|---|---|
| AQA GCSE 8300 | G3 | Apply the properties of angles at a point, angles at a point on a straight line, vertically opposite angles |
| Edexcel GCSE 1MA1 | G3 | Apply the properties of angles at a point, angles at a point on a straight line, vertically opposite angles; understand and use alternate and corresponding angles on parallel lines; derive and use the sum of angles in a triangle (e.g. to deduce and use the angle sum in any polygon, and to derive properties of regular polygons) |
| Eduqas GCSE C300 | FG3 | Apply the properties of angles at a point, angles at a point on a straight line, vertically opposite angles; understand and use alternate and corresponding angles on parallel lines; derive and use the sum of angles in a triangle (e.g. to deduce and use the angle sum in any polygon, and to derive properties of regular polygons) |
| Eduqas GCSE C300 | HG3 | Apply the properties of angles at a point, angles at a point on a straight line, vertically opposite angles; understand and use alternate and corresponding angles on parallel lines; derive and use the sum of angles in a triangle (e.g. to deduce and use the angle sum in any polygon, and to derive properties of regular polygons) |
| Edexcel IGCSE 4MA1 | F4.1B | Use angle properties of intersecting lines, parallel lines and angles on a straight line |
| Cambridge IGCSE 0580 | C4.6 | Angles |
| Cambridge IGCSE 0580 | E4.6 | Angles |
| OCR GCSE J560 | 8.03a | Know and use the sum of the angles at a point is 360°. |
| OCR GCSE J560 | 8.03b | Know that the sum of the angles at a point on a line is 180°. |
| OCR GCSE J560 | 8.03c | Know and use: vertically opposite angles are equal; alternate angles on parallel lines are equal; corresponding angles on parallel lines are equal. |
For teachers
This GCSE Maths lesson teaches angles on parallel lines. By the end, students should be able to identify alternate, corresponding and co-interior (allied) angles on parallel lines by their correct formal name, use them to find missing angles, and only apply them once parallelism is actually established. It works through two worked examples and the mistakes examiners report.