- Definition
When two lines or surfaces meet to form a perfect square corner, they are perpendicular.
The side and bottom edges of a square are perpendicular because they meet at a 90° angle.
How to teach this in 30 seconds
Try this analogy: Perpendicular lines are like the corner of a book, where the top edge and the side edge meet to make a perfect square corner.
Ask your child: Where can you find a perfect corner in this room?
Common mix-up: Kids often think any two lines that cross are perpendicular. The key is that perpendicular lines must meet to form a perfect square corner, like the letter T.
Examples
- The vertical and horizontal lines on a window pane.
- Where the floor meets the wall in a room.
- The lines that form the plus sign '+' are perpendicular.
perpendicular 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 ↗
