Mathematics

Intermediate

50 mins

Teacher/Student led

Learning Goals

Learning Outcomes

Lesson Files

+80 XP

What you need:
IWB/Projector/Large Screen

Reflecting a Shape Across a Line

Learn how to flip a shape across a mirror line so it faces the opposite way, keeping every corner the same distance from the line. Work through reflections across vertical, horizontal and diagonal lines.

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

1 - Getting Started ~4 mins

Illustration for Getting Started Look at this picture of a pattern-block triangle standing beside a mirror. The triangle points to the right. Its reflection sits in the mirror.

Which way is the reflection pointing? The same way as the triangle, or the opposite way? Have a good look before any hands go up.

👇 Mark your steps as done as you complete them.

+5 XP

2 - Watch and Notice ~12 mins

The interactive reflects each shape across a mirror line. Watch which way the shape flips, and count the squares from the line to a corner and back the same distance on the other side.

👇 Mark your steps as done as you complete them.

+10 XP

3 - Try It Together ~8 mins

Today we explore reflections on the board. We build a small shape on one side of the mirror line, and the tool flips it across to the other side. Watch where each flipped corner lands.

Key point

We will try a triangle across a line, then an L-shape, checking each time that every corner is the same distance from the line.

Reflect the shape across the line

+15 XP

4 - Draw the Reflection in Your Copy ~3 mins

COPYBOOK MOMENT

Illustration for Draw the Reflection in Your Copy In your maths copy on squared paper, draw a vertical mirror line. On the left of the line, draw a flag shape. Then carefully draw its reflection on the right.

Check each corner: count how many squares the corner is from the line, then count the same number on the other side. Every corner must be the same distance from the line.

+10 XP

5 - Class Challenge ~10 mins

Key point

Today we work through these reflections together. Remember: a reflection flips the shape; it is never just slid along.

Reflect a triangle across a vertical line.
Reflect the triangle across a horizontal line.
Reflect an arrow so it points the opposite way.
Reflect a shape that touches the line.

Tip

If we have time, there is an optional stretch: reflect an L across a diagonal line.

Reflect each shape across the line

+15 XP

Pupil practice

Module 8 · Symmetry, Location and Transformation Shape & Space

Lesson 93 · Reflecting a Shape Across a Line

Download Activity Book page (PDF)

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