Jungle maths quest: perimeter
A story-led junior maths adventure using bridges, vines and hidden temples to measure fences, walls and safe zones around places.
Quick answer
Perimeter is the total distance around the edge of a shape. You can find it by adding up all the sides of a shape.
Learning outcome
By the end of this page, you will be able to measure the perimeter of different shapes by adding up all the sides.
- You can identify the sides of a shape
- You can add up all the sides to find the perimeter
- You can measure and calculate the perimeter of rectangles and other shapes
- You can solve simple problems about perimeter in real life
Why this matters
Perimeter is like measuring how far you walk around the edge of a shape. It helps you know how much fencing you need for a garden, how much rope you need to go around a play area, or how far you walk around a jungle path. In your daily life, you use perimeter when you help plan a picnic area, build a fence, or even when you're playing games!
How it works
Perimeter is the distance all the way around a shape. To find it:
- Look at each side of the shape
- Measure or count each side
- Add all the sides together
It's like going for a walk around the outside of a shape and counting how many steps you take. Each side is one step.
Examples you can see
Let's imagine you're on a jungle adventure and you need to build a bridge to cross a river. You must measure how long your bridge needs to be. Here are some examples:
Example 1: A Rectangle
Imagine a rectangular jungle clearing where you want to build a fence. The rectangle is 5 metres long and 3 metres wide.
| Side | Length |
|---|---|
| Long side | 5 m |
| Long side | 5 m |
| Short side | 3 m |
| Short side | 3 m |
Perimeter = 5 + 5 + 3 + 3 = 16 metres
Example 2: A Triangle
Imagine a triangular jungle path that you want to measure. The sides are 4 m, 5 m, and 6 m.
Perimeter = 4 + 5 + 6 = 15 metres
Example 3: A Square
Imagine a square jungle temple. Each side is 7 metres.
Perimeter = 7 + 7 + 7 + 7 = 28 metres
Example 4: A Regular Pentagon
Imagine a pentagon-shaped jungle hideout where each side is 4 metres.
Perimeter = 4 + 4 + 4 + 4 + 4 = 20 metres
Try it as a mini adventure
Imagine you are a jungle explorer and you need to build a safe zone for your animal friends. You have a map of your jungle area with different shapes. You need to find the perimeter of each shape to know how much rope you need to make a fence.
Adventure Steps:
- You start at the rectangle jungle clearing (5 m by 3 m)
- Next, you go to the triangle path (4 m, 5 m, 6 m)
- Then you visit the square temple (7 m each side)
- Finally, you reach the pentagon hideout (4 m each side)
Challenge Questions:
4th time: What is the perimeter of the rectangle? Answer: 16 m
5th time: What is the perimeter of the triangle? Answer: 15 m
6th time: What is the perimeter of the square? Answer: 28 m
7th time: What is the perimeter of the pentagon? Answer: 20 m
Common mistakes
- Mistake: Forgetting to measure all sides of a shape
Why it happens: When you're excited about your adventure, you might skip counting some sides.
Fix: Use a finger or a stick to trace each side while counting it.
- Mistake: Adding up the area instead of the perimeter
Why it happens: Area and perimeter sound similar, so it's easy to mix them up.
Fix: Remember perimeter is the distance around the edge, not the inside space.
- Mistake: Not using the same units for all sides
Why it happens: Sometimes you might measure one side in metres and another in centimetres.
Fix: Always convert measurements to the same unit before adding them.
Parent and carer guide
Helping your child with perimeter is like going on a jungle adventure together! Here's how you can support them in 5-10 minutes:
- Ask questions: "How many sides does this shape have?" or "What do you think the perimeter will be?"
- Use real objects: Measure the perimeter of your dining table, a book, or a picture frame at home.
- Draw and count: Draw shapes and have your child count each side to find the perimeter.
- Encourage measurement: Use rulers or a tape measure to help them find actual lengths.
- Be patient: It's normal for children to make mistakes at first. They're learning!
Remember, perimeter is about the outside edge. If you're building a fence or walking around a shape, you're measuring the perimeter.
Practice questions
- What is the perimeter of a rectangle that is 6 m long and 4 m wide?
- What is the perimeter of a triangle with sides of 5 m, 7 m, and 8 m?
- What is the perimeter of a square with each side 9 m?
- What is the perimeter of a pentagon with each side 5 m?
- What is the perimeter of a hexagon with each side 3 m?
Answers:
- Perimeter = 6 + 6 + 4 + 4 = 20 m
- Perimeter = 5 + 7 + 8 = 20 m
- Perimeter = 9 + 9 + 9 + 9 = 36 m
- Perimeter = 5 + 5 + 5 + 5 + 5 = 25 m
- Perimeter = 3 + 3 + 3 + 3 + 3 + 3 = 18 m
FAQ
What is perimeter?
Perimeter is the total distance around the edge of a shape. You can find it by adding up all the sides of a shape.
How do I find the perimeter of a rectangle?
Measure the length and width, then add them together twice. For example, a rectangle with sides 5 m and 3 m has a perimeter of 5 + 5 + 3 + 3 = 16 m.
Can I find the perimeter of any shape?
Yes! You can find the perimeter of any shape as long as you can measure or count all the sides around the outside.
Why is perimeter useful in real life?
Perimeter helps you know how much fencing you need for a garden, how much rope to go around a play area, or how far you walk around a path. It's useful for planning and building!
What's the difference between perimeter and area?
Perimeter is the distance around the outside of a shape, while area is the space inside the shape. Think of perimeter as the edge of a fence, and area as the grass inside the fence.