Year 8 - Maths
Checking understanding of angles from KS2
Geometrical properties: polygons
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This pupil-friendly study guide includes a unit summary, clear notes, common mistakes, and quick questions with answers.
Unit Summary
In this unit pupils will investigate internal and external angles of polygons and angles made with a transveral and parallel lines. Pupils will develop their ability to formally prove properties of polygons to generalise.
Lesson Summary
You will learn to calculate with angles at a point, angles on a line and vertically opposite angles.
Key Notes
- Angles that meet at a point can be identified in diagrams.
- Angles that make a straight line can be identified on a diagram.
- Vertically opposite angles can be identified on a diagram.
Vocabulary To Learn
- Supplementary angles: Supplementary angles are a pair of angles that sum to 180°.
- Conjugate angles: Conjugate angles are a pair of angles that sum to 360°.
Common Mistakes To Avoid
- In order for two angles to be supplementary, they must both lie about a point on a straight line.
3 Quick Questions (With Answers)
1. Solve this in steps: explain the method from this lesson and why each step matters.
Angles that meet at a point can be identified in diagrams. Angles that make a straight line can be identified on a diagram.
2. Use this key word in a maths sentence and explain it clearly. 'Supplementary angles'
Supplementary angles are a pair of angles that sum to 180°. Use this word when showing your method, then check your final answer is reasonable.
3. Spot and fix this common maths mistake.
Mistake: In order for two angles to be supplementary, they must both lie about a point on a straight line. Correction: For two angles to be supplementary, they must sum to 180°. They do not also need to both lie on a straight line.
More Lessons In This Unit
- Alternate angles Study Guide
- Angles on parallel lines traversed by a straight line Study Guide
- Co-interior angles Study Guide
- Corresponding angles Study Guide
- Deriving the sum of interior angles in multiple ways Study Guide
- Exterior angles of polygons Study Guide
- Formal angle notation Study Guide
- Formalising understanding of triangles from KS2 Study Guide
- Interior and exterior angles of regular polygons Study Guide
- Interior angles of a polygon Study Guide
- Missing angles Study Guide
- Problem solving with polygons Study Guide
- Securing understanding of angles from KS2 Study Guide
- The sum of the interior angles of any triangle Study Guide
- Using the sum of the interior angles of a triangle Study Guide
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