Year 10 - Maths
Checking and securing understanding of interior angles
Angles
Study Hub
Study Guides
This pupil-friendly study guide includes a unit summary, clear notes, common mistakes, and quick questions with answers.
Unit Summary
In this unit pupils use their knowledge of corresponding, alternate and co-interior angles to reason through and solve more complicated problems.
Lesson Summary
You will learn to find the interior angle of any regular polygon or deduce the interior angle of an irregular polygon.
Key Notes
- Any polygon can be split into triangles.
- Using these triangles you can demonstrate the rule for the interior angle sum of a polygon.
- A missing interior angle in any polygon can be found.
- The number of sides in a regular polygon can be determined from the size of the interior angle.
- The sum of the interior angles is the same, regardless of whether the polygon is regular.
Vocabulary To Learn
- Polygon: A polygon is a flat (2D), closed figure made up of straight line segments.
- Regular: A regular polygon has sides that are all equal and interior (inside) angles that are all equal.
- Interior angle: An interior angle is an angle formed inside a polygon by two of its edges.
Common Mistakes To Avoid
- The size of an interior angle in a regular shape cannot be found unless the size of the other angles are given.
3 Quick Questions (With Answers)
1. Solve this in steps: explain the method from this lesson and why each step matters.
Any polygon can be split into triangles. Using these triangles you can demonstrate the rule for the interior angle sum of a polygon.
2. Use this key word in a maths sentence and explain it clearly. 'Polygon'
A polygon is a flat (2D), closed figure made up of straight line segments. Use this word when showing your method, then check your final answer is reasonable.
3. Spot and fix this common maths mistake.
Mistake: The size of an interior angle in a regular shape cannot be found unless the size of the other angles are given. Correction: A regular shape has the property that all of its interior angles are equal in size. This means that the size of each interior angle is very easy to find if, for example, the sum of the interior angles is known.
More Lessons In This Unit
- Checking and securing understanding of advanced angle facts Study Guide
- Checking and securing understanding of angle notation and drawing/measuring angles Study Guide
- Checking and securing understanding of basic angle facts Study Guide
- Checking and securing understanding of exterior angles Study Guide
- Checking and securing understanding of polygons Study Guide
- Checking and securing understanding of properties of shapes Study Guide
- Checking and securing understanding on chains of reasoning with angle facts Study Guide
- Forming equations with angles Study Guide
- Problem solving with angles Study Guide
Browse all guides in the Year 10 Maths guide library.