- Definition
An edge is where two flat surfaces (called faces) of a 3D shape meet, like the line where two sides of a box come together.
A cube has 12 edges where its square faces meet.
How to teach this in 30 seconds
Try this analogy: An edge on a 3D shape is like the crease you make when you fold a piece of paper.
Ask your child: Can you run your finger along an edge of this book?
Common mix-up: Kids often confuse an edge with a corner. An edge is the straight line where two flat faces meet, not the pointy part where the lines themselves meet.
Examples
- The spine of a closed book is one of its edges.
- A pyramid has edges where its triangular faces meet each other and the base.
edge 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 ↗
