Perimeter
The distance around a shape, and the formulas for a rectangle and square. 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
Perimeter
Perimeter is the distance around a shape. Add all the sides.
- Rectangle: P = 2 × (l + b): 2 × (5 + 3) = 16 cm.
- Square: P = 4 × s.
- Perimeter units are plain: cm, m.
Comparing perimeter and area
The same area can have different perimeters. All three of these rectangles have an area of 16 cm²:
| Rectangle | Area | Perimeter |
|---|---|---|
| 4 cm × 4 cm | 16 cm² | 16 cm |
| 8 cm × 2 cm | 16 cm² | 20 cm |
| 16 cm × 1 cm | 16 cm² | 34 cm |
The square has the smallest perimeter for the same area.
Remember this and test yourself
- Perimeter = distance around a shape.
- Perimeter: add all the sides.
- Perimeter of a rectangle: 2 × (l + b); of a square: 4 × s.
- Perimeter units are plain: cm, m.
Write these points in your book. Read them again the night before the test.
PERIMeter: walk around the RIM.
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.
True or false?
Read the question and the answer. Is the answer right? Tap True or False.
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: Perimeter- 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 6 Mathematics. Always check your teacher’s notes and textbook too.