- Definition
A shape has line symmetry if you can fold it in half perfectly, so both sides match up exactly. The fold line is called the line of symmetry.
A square has four lines of symmetry: one vertical, one horizontal, and two diagonal.
How to teach this in 30 seconds
Try this analogy: Line symmetry is like folding a piece of paper in half to cut out a heart, where the fold is the line of symmetry.
Ask your child: How many ways could you fold this shape so both halves match exactly?
Common mix-up: Kids may think any line that cuts a shape in half works. For line symmetry, the halves must be perfect mirror images of each other.
Examples
- A capital letter 'A' has one vertical line of symmetry down its middle.
- A capital letter 'F' has no line of symmetry because no fold line creates matching halves.
- The capital letter 'E' has one horizontal line of symmetry through its middle bar.
line symmetry is a term used in Ontario’s Kindergarten to Grade 8 curriculum.
Where this shows up
The descriptions on this page are SmartStudy’s own original, plain-language writing — not the Ministry’s wording. They are aligned to the Ontario Curriculum, © King’s Printer for Ontario. For the Ministry’s official wording, see the source link below. SmartStudy is an independent service and is not affiliated with, endorsed by, or sponsored by the Government of Ontario or the Ministry of Education. Ontario Curriculum and Resources ↗
