Good Learning Co.
SavannahYear 8

Year 4 · Measures, time and graphs

Lines of symmetry

Identify lines of symmetry in 2-D shapes presented in different orientations

20 minutes4 checks6 exit questionsNational curriculum objective

Lesson overview

What you'll learn in this lesson

Identify lines of symmetry in 2-D shapes presented in different orientations

Key learning points

  • • The fold test
  • • How many for each shape?
  • • Turning the shape does not change it
  • • Completing a pattern

This lesson at a glance

  • 20 minutes
  • 19 parts to scroll through
  • 4 quick checks
  • No marked quiz yet
  • Gentle pace: short sittings with pauses

Words to know

symmetryshapespresentedorientationsturning

Scroll down — the lesson carries on below

Part 1 of 19 · Discover5%
1

Watch & discover

Part 1 of 19

Silent film

Watch first

Lines of symmetry

Measuring round the edge, covering the inside, then reading the clock.

Read the film in words (English) ↓

What the film shows

  1. A finger traces the edge of a rectangle while the perimeter total counts up.
  2. The same rectangle fills with unit squares to show its area.
  3. Units convert on screen: centimetres to metres, grams to kilograms, millilitres to litres.
  4. A 12-hour clock and a 24-hour clock show the same moment side by side, then a bar chart is read off.
  5. The perimeter and unit-swap practicals for this unit repeat all of this with a tape measure.

Do it for real

The practicals below use what the film shows, with a full method you can follow at home.

Same perimeter, different areaGrams, millilitres and a fair biscuit test

In a nutshell

Identify lines of symmetry in 2-D shapes presented in different orientations

2

What you already know

Part 2 of 19

Before we start

What you already know

You can name 2-D shapes and their sides and corners.

3

Key words

Part 3 of 19

Key words

Words you'll need today

line of symmetry
A fold line where both halves match exactly.
reflection
The mirror image on the other side of the line.
orientation
The way a shape is turned.
4

Learning cycle

Part 4 of 19

Learning cycle 1 of 2

Part 1 — Finding fold lines

A short piece of teaching, then a check to make sure it has landed.

5

Explore the idea

Part 5 of 19

Learn

The fold test

Cut out a square and fold it in half top to bottom: the halves match, so that is a line of symmetry. A square has four in total — two through the middles of the sides and two through the corners. If the halves do not match, it is not a line of symmetry, however tidy it looks.

6

Explore the idea

Part 6 of 19

Learn

How many for each shape?

A rectangle that is not a square has 2. An equilateral triangle has 3. A regular pentagon has 5, a regular hexagon 6 — a regular shape has as many lines as it has sides. A circle has endlessly many. A scalene triangle has none at all.

7

Quick check

Part 7 of 19

Quick check

How many lines of symmetry does a square have?

8

Quick check

Part 8 of 19

Quick check

A rectangle 6 cm by 3 cm has how many?

9

Reset break

Part 9 of 19

Pause

That's sitting 1 of 2 done

Stretch, get a drink, look out of the window. There is no timer and nothing is counting down — your place is saved, so you can come back in five minutes or tomorrow.

Stop here for now
10

Learning cycle

Part 10 of 19

Learning cycle 2 of 2

Part 2 — Turned shapes and patterns

A short piece of teaching, then a check to make sure it has landed.

11

Explore the idea

Part 11 of 19

Learn

Turning the shape does not change it

Draw a square balanced on one corner like a diamond. It still has four lines of symmetry — they have simply turned with the shape. This is the part tests love: the shape is the same shape whichever way round it is printed.

12

Explore the idea

Part 12 of 19

Learn

Completing a pattern

Given half a pattern and a mirror line, count squares out from the line to place each part on the other side. Two squares left of the line means two squares right of it, at the same height. Working square by square is slower but far more accurate than eyeballing it.

13

Quick check

Part 13 of 19

Quick check

How many does an equilateral triangle have?

14

Quick check

Part 14 of 19

Quick check

A square turned to look like a diamond has how many?

15

Common mix-ups

Part 15 of 19

Common mix-ups

Things people often get wrong

  • Thinking a diagonal line across a non-square rectangle is a line of symmetry — fold it and the halves do not match.
  • Believing a turned shape loses its symmetry.
  • Counting only the vertical fold line and stopping there.
16

Challenge round

Part 16 of 19

Game · Sort it

Which of these are true?

Drag each card into the right column. Tap a card first if dragging is fiddly.

True

Not true

17

Challenge round

Part 17 of 19

Game · Fill the gaps

Finish the sentences

Choose the word that belongs in each gap.

Cut out a square and fold it in half top to bottom: the halves match, so that is a line of ____.

18

Mastery quiz

Part 18 of 19

No quiz for this one

This lesson has no marked quiz attached yet.

19

Lesson round-up

Part 19 of 19

Lesson round-up

Ready when you are

Quiz score

Not sat

Games

Not played

Points this lesson

0

Best run

0 in a row

Luna: 0 out of 4 on the practice checks. Only if you feel up to it — one more?

Ask Luna

Do the work

Your written work for this lesson

This is the part you'd do in your book at school. Pick the pieces below, write here or on paper, and photograph anything you draw or work out.

Article

The cost of a school trip

A school is planning a trip to a wildlife park. The coach costs £480 however many people go. Entry costs £9.50 for each pupil and each adult goes free. The school says every pupil must pay the same amount, and the trip must not lose money.

If 60 pupils go, the coach works out at £8 each, so the total for each pupil is £17.50. If only 40 pupils go, the coach works out at £12 each, so the price rises to £21.50. The teacher explains that the coach is a fixed cost and the entry is a cost per person — which is why the price per pupil changes when the number changes.

The school decides to charge £20 and to use anything left over for a second trip later in the year.

Written for Good Learning Co.

Reading questions

  1. Work out the total cost of the trip if 50 pupils go.
  2. Show why the price per pupil falls when more pupils go, using numbers.
  3. At £20 each, how many pupils must go before the trip makes money? Show your working.

  • Working out

    Working out

    Do the practice questions on paper, showing every step — not just the answer. Mark them yourself and circle anything you got wrong.

    10–15 questions

  • Worked example, explained

    Writing

    Copy one question out and write underneath, in words, why each step works.

    1 question, 4–5 sentences

  • Problem in words

    Working out

    Write your own real-life problem that uses today's method, then solve it.

    1 problem + solution

Saved as you type.

Part 1 of 19 · Watch & discover

Next

Back to your Year 4 units, or a few minutes of quick practice.

All Year 4 unitsSkills quest
Good Learning Co. — personalised UK curriculum learning, built around what each learner loves.