Idea 3of 22Builds onPerimeter is the distance around
Fence or floor: which measure?
Does a job need the area or the perimeter?
Today you'll discover
- which jobs follow the edge
- which jobs cover the inside
- a question to ask every time
Think firstA garden 6 m long and 4 m wide
To put a fence around the garden, which do you need?
Decide first, then press Next. Ask: does the job go along the edge, or cover the inside?
A garden 6 squares by 4 squares, each square 1 m by 1 m, sides marked 6 m and 4 m. A thick orange fence line goes round it: 20 m. Then tinted squares fill it: 24 m². The last step shows a bedroom floor 5 m by 4 m.
See the whole ideathe big idea and the key word, in one place
The big idea
Fences and borders need the perimeter; carpet, paint and soil need the area.
For examplePerimeter jobs: a fence, a picture frame, lights around a window. Area jobs: carpet, paint for a wall, grass seed for a lawn.
Easy to get wrongThe same two numbers, 6 and 4, give both answers. The job decides whether you add the sides or multiply them.
Key word
- boundary
- the edge all the way around a shape
Ready to use it?
- Decide whether a job needs area or perimeter.