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.
These resources will be removed by end of Summer Term 2025.
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.
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.
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.
To help you plan your year 4 maths lesson on: Find lines of symmetry in 2D shapes, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your year 4 maths lesson on: Find lines of symmetry in 2D shapes, download all teaching resources for free and adapt to suit your pupils' needs.
The starter quiz will activate and check your pupils' prior knowledge, with versions available both with and without answers in PDF format.
We use learning cycles to break down learning into key concepts or ideas linked to the learning outcome. Each learning cycle features explanations with checks for understanding and practice tasks with feedback. All of this is found in our slide decks, ready for you to download and edit. The practice tasks are also available as printable worksheets and some lessons have additional materials with extra material you might need for teaching the lesson.
The assessment exit quiz will test your pupils' understanding of the key learning points.
Our video is a tool for planning, showing how other teachers might teach the lesson, offering helpful tips, modelled explanations and inspiration for your own delivery in the classroom. Plus, you can set it as homework or revision for pupils and keep their learning on track by sharing an online pupil version of this lesson.
Explore more key stage 2 maths lessons from the Properties of 2D and 3D shapes and symmetry unit, dive into the full secondary maths curriculum, or learn more about lesson planning.
Licence
Lesson video
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Starter quiz
6 Questions
Exit quiz
6 Questions
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4
4 lines of symmetry
3 lines of symmetry
5 lines of symmetry
8 lines of symmetry
6 lines of symmetry