A shape has line symmetry if it can be divided into two mirror image halves by a line drawn through the shape. The document explores line symmetry in different shapes such as squares, which have 4 lines of symmetry, triangles and other polygons that can have 1, 2, or more than 2 lines of symmetry depending on their design. By investigating joining shapes together, students can determine how many total lines of symmetry a combined shape might have.

1. Line Symmetry
Year 4

2. A shape has line symmetry if…
You can draw a line through it so that one part is exactly
the same as the other part.

3. These shapes have one line of
symmetry

4. These shapes have two lines of
symmetry

5. Some shapes have more than 2
lines of symmetry
How many lines of
symmetry has a square got?

6. Watch!
A square has 4 lines of symmetry

7. How many lines of symmetry
does this shape have?
0
1
2
More than 2

8. Watch!
This shape has 1 line of symmetry

10. But how many lines of symmetry
does this shape have?
0
1
2
More than 2

11. Watch!
This shape has 2 lines of symmetry

13. How many lines of symmetry
does this shape have?
0
1
2
More than 2

14. Watch!
This shape has 3 lines of symmetry

16. But how many lines of symmetry
does this shape have?
0
1
2
More than 2

17. Watch!
This shape has only 2 lines of symmetry

19. What happens when…
…you join two shapes together?
Investigate.