Year 3 - Maths
Know that a rectangle is a four-sided polygon with four right angles
Right angles
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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 rotate 2 lines around a fixed point to make different angles. They identify vertices and describe half, quarter and three-quarter turns in terms of right angles.
Lesson Summary
You will learn to identify a rectangle as a four-sided polygon with four right angles.
Key Notes
- A polygon is a 2D shape made up of 3 or more sides.
- A rectangle is a 4-sided polygon with 4 right angles.
- A 4-sided shape with fewer than 4 right angles is not a rectangle.
- A right angle is marked with a symbol inside the angle.
Vocabulary To Learn
- Polygon: A polygon is a 2D shape made up of 3 or more straight sides.
- Rectangle: A rectangle is a 2D shape with four straight sides and four right angles.
Common Mistakes To Avoid
- Pupils need to look at the interior angles in the shape. They may think that an interior angle of 270° is a right angle.
3 Quick Questions (With Answers)
1. Solve this in steps: explain the method from this lesson and why each step matters.
A polygon is a 2D shape made up of 3 or more sides. A rectangle is a 4-sided polygon with 4 right angles.
2. Use this key word in a maths sentence and explain it clearly. 'Polygon'
A polygon is a 2D shape made up of 3 or more straight sides. Use this word when showing your method, then check your final answer is reasonable.
3. Spot and fix this common maths mistake.
Mistake: Pupils need to look at the interior angles in the shape. They may think that an interior angle of 270° is a right angle. Correction: Explain to pupils that we need to measure the interior angles of a shape. Show them examples of this (e.g. an arrowhead) to illustrate.
More Lessons In This Unit
- Identify and describe right angles Study Guide
- Identify properties of quadrilaterals Study Guide
- Identify properties of triangles Study Guide
- Investigate and draw other polygons with right angles Study Guide
- Investigate the shapes made when rectangles are cut on the diagonal Study Guide
- Join four right angles at a point using different right-angled polygons Study Guide
- Know that a right angle describes a quarter turn Study Guide
- Know that a square is a rectangle in which the four sides are of equal length Study Guide
- Make different sized angles by rotating two lines around a fixed point Study Guide
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