Mathematics

Intermediate

50 mins

Teacher/Student led

Learning Goals

Learning Outcomes

Lesson Files

+80 XP

What you need:
IWB/Projector/Large Screen
Paper shapes

Line Symmetry: Finding Lines of Symmetry

Explore lines of symmetry by folding shapes and letters so their two halves match exactly. Test whether each fold is a true line of symmetry and discover how many lines different shapes have.

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1 Getting Started
2 Watch and Notice
3 Try It Together
4 Rule the Lines in Your Copy
5 Class Challenge
6 What Did We Notice?
7 What's Next
Pupil practice

1 - Getting Started ~5 mins

Illustration for Getting Started Watch as I fold this paper heart straight down the middle. The fold I make is a mirror line: the line we test to see whether the two halves match. Look closely: the two halves land exactly on top of each other, like a mirror.

Key point

A square is different. Where could you fold a square so that both halves match perfectly? Is there only one fold that works, or could there be more than one?

👇 Mark your steps as done as you complete them.

+5 XP

2 - Watch and Notice ~11 mins

Watch the mirror line move across four shapes: a square, a rectangle, the letter X and the letter T. Each fold either makes two halves that match or it doesn't. Count how many folds match for each one.

👇 Mark your steps as done as you complete them.

+10 XP

3 - Try It Together ~13 mins

Today we explore: tap to place the mirror line, the fold line we test, on each shape and letter to see whether the two halves match. We will work through a square, a rectangle, the letter T and the letter X on the shared board.

Key point

When the fold makes both halves land exactly on top of each other, we have found a line of symmetry. When they miss, that fold does not count.

Test the fold lines

+15 XP

4 - Rule the Lines in Your Copy ~5 mins

COPYBOOK MOMENT

In your maths copy, draw a square, a rectangle and the letter X. Then rule in every line of symmetry you can find on each one. Use the straight edge of your ruler to keep your lines neat.

+10 XP

5 - Class Challenge ~10 mins

Today we work through these together: the letter H, the letter X, the letter S and the letter M.

Watch out

Watch out — one of them has no line of symmetry at all, so check every fold carefully before you decide.

Find every line of symmetry

+15 XP

Pupil practice

Module 8 · Symmetry, Location and Transformation Shape & Space

Lesson 91 · Line Symmetry: Finding Lines of Symmetry

Download Activity Book page (PDF)

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