Symmetry
Lines of symmetry: mirror images on both sides. Read one part at a time and tap “I know this”. Then test yourself in the quiz.
Know it already? Jump straight to the quiz
Line symmetry
A shape is symmetrical if a line of symmetry splits it into two halves that are exact mirror images.
| Shape | Lines of symmetry |
|---|---|
| square | 4 |
| rectangle | 2 |
| equilateral triangle | 3 |
| isosceles triangle | 1 |
| scalene triangle | 0 |
| kite | 1 |
| rhombus | 2 (its diagonals) |
| parallelogram | 0 |
| regular pentagon | 5 |
| regular hexagon | 6 |
| circle | infinitely many |
A rectangle has 2 lines of symmetry (through the middles of opposite sides). Its diagonals are not lines of symmetry.
- Lines of symmetry can be vertical, horizontal or slanted.
- Letters: A has 1 line of symmetry, H has 2, F has 0.
- To complete a symmetrical drawing: copy each point the same number of blocks on the other side of the mirror line.
Remember this and test yourself
- A line of symmetry splits a shape into mirror halves.
- Square 4 lines; rectangle 2; isosceles triangle 1.
- A parallelogram has no line of symmetry; a rectangle’s diagonals are not lines of symmetry.
Write these points in your book. Read them again the night before the test.
Fold on the line: do the halves match exactly? Symmetrical!
Important words
First say the answer yourself, then turn the card over.
Match column A to column B
Tap a word in column A, then its meaning in column B. You can also start in column B.
Now the real quiz!
The quiz has many more questions on this topic. Every question shows straight away whether you are right and explains why.
Take the quiz: Symmetry- Let your child work the examples on paper and explain them to you.
- The ticks (“I know this”) are saved on this device only. We never ask for names or emails.
Follows CAPS for Grade 5 Mathematics. Always check your teacher’s notes and textbook too.