Find lines of symmetry in 2D shapes
I can find lines of symmetry in 2D shapes and explain the link between lines of symmetry and number of sides in regular polygons.
Find lines of symmetry in 2D shapes
I can find lines of symmetry in 2D shapes and explain the link between lines of symmetry and number of sides in regular polygons.
Lesson details
Key learning points
- A line of symmetry splits the shape into two equal parts which are mirror images.
- Shapes are symmetrical when they look the same when a mirror is placed on the mirror line.
- Regular polygons have the same number of lines of symmetry as they have sides.
Common misconception
Children may not identify lines of symmetry that are neither horizontal nor vertical.
Allow opportunities for children to handle and manipulate cut outs of shapes so that they can try to find lines of symmetry in different orientations. Encourage them to describe the position of the line of symmetry to support their understanding.
Keywords
Symmetrical - When a shape, pattern or image has one half that is the reflection of the other half, it can be described as symmetrical.
Line of symmetry - If you were to fold a shape on its line of symmetry, both halves would match exactly.
Regular polygon - A regular polygon has sides that are all equal and angles that are all equal.
Licence
This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).
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Starter quiz
6 Questions
Exit quiz
6 Questions
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2
4
4 lines of symmetry
3 lines of symmetry
5 lines of symmetry
8 lines of symmetry
6 lines of symmetry