Maths Adventures
Volcano maths quest: perimeter
A story-led junior maths adventure using lava paths, safety zones and eruption data 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 and calculate the perimeter of different shapes around the volcano. Success signs:- You can name the sides of a shape and add them up to find the perimeter
- You can use a ruler or measuring tape to measure each side
- You can work out the perimeter of a rectangle or square
- You can imagine how far you would walk around the edge of a shape
Why this matters
When you're on a volcano adventure, knowing how far you need to walk around a safe zone or fence is very useful. If you're planning a garden or building a wall, you need to know how much material you'll need. Perimeter helps you measure how much space something takes up around the outside.How it works
To find the perimeter of any shape, you simply add up the lengths of all the sides. Let's look at some simple shapes: For a rectangle:- Measure the length of the long sides
- Measure the length of the short sides
- Add all four sides together
- Measure one side
- Multiply that side by 4 (because all sides are equal)
- Measure each side
- Add all the measurements together
Examples you can see
Let's go on a volcano adventure! Imagine you're exploring a volcano and you need to walk around a safe zone to avoid lava. Example 1: Square Safe Zone You find a square safe zone with each side measuring 5 metres.- Side 1: 5 metres
- Side 2: 5 metres
- Side 3: 5 metres
- Side 4: 5 metres
- Long side: 8 metres
- Long side: 8 metres
- Short side: 4 metres
- Short side: 4 metres
- Side 1: 6 metres
- Side 2: 7 metres
- Side 3: 5 metres
Try it as a mini adventure
Volcano Maths Quest: The Safe Zone Challenge You are a brave explorer who has discovered a new volcano! But the lava is very active, so you need to find the safest place to build your base camp. Your mission:- Find a square safe zone that is 3 metres on each side
- Measure the perimeter of this square
- Draw a rectangle that is 6 metres long and 3 metres wide
- Calculate the perimeter of your rectangle
- Find a triangular danger zone with sides of 4 metres, 5 metres, and 3 metres
- Measure the perimeter of the triangle
Common mistakes
- Mistake: Forgetting to measure all sides of a shape
Why it happens: When we're in a hurry or excited, we might skip counting one side.
Fix: Use your finger to trace around the shape and count each side as you go. - Mistake: Adding the length and width instead of all sides
Why it happens: Some children think that for rectangles, we just add length and width.
Fix: Remember: perimeter = all sides added together, not just length + width. - Mistake: Not using the same units when measuring
Why it happens: Some children mix up centimetres and metres.
Fix: Always make sure all your measurements are in the same unit before adding. - Mistake: Confusing perimeter with area
Why it happens: Both are measurements of shapes, so they can be mixed up.
Fix: Remember: perimeter is around the edge, area is inside the shape.
Parent and carer guide
As a parent or carer, you can help your child learn about perimeter by:- Using everyday objects to practice measuring, like books, boxes, or tables
- Playing the perimeter game: "How far would we walk around our kitchen?"
- Looking at floor plans or maps together and calculating distances
- Using a ruler or measuring tape to measure real objects
- Encouraging your child to explain how they found the perimeter
- Noting if they're counting all sides or missing some
- Reinforcing that perimeter is the distance around the outside
- Does your child count all sides of the shape?
- Are they using the correct units (metres, centimetres)?
- Do they understand that perimeter is a distance around the shape?
- Ask questions like "What do you think the perimeter is?" instead of "What's the answer?"
- Give praise for trying and thinking through the problem
- Use real-life examples from your home or daily life
- Make it fun by turning it into a game or adventure
Practice questions
- What is the perimeter of a square with sides of 4 metres?
- A rectangle has sides of 7 metres and 3 metres. What is its perimeter?
- What is the perimeter of a triangle with sides of 5, 6, and 4 metres?
- Find the perimeter of a square with sides of 2 metres.
- Calculate the perimeter of a rectangle that is 9 metres long and 5 metres wide.
- 4 + 4 + 4 + 4 = 16 metres
- 7 + 7 + 3 + 3 = 20 metres
- 5 + 6 + 4 = 15 metres
- 2 + 2 + 2 + 2 = 8 metres
- 9 + 9 + 5 + 5 = 28 metres
FAQ
What is perimeter?
Perimeter is the total distance around the edge of a shape. You can think of it like walking all the way around the outside of a shape.
How do you find the perimeter of a rectangle?
To find the perimeter of a rectangle, you add up all four sides. If it's 6 metres long and 4 metres wide, the perimeter is 6 + 6 + 4 + 4 = 20 metres.
Can you find the perimeter of any shape?
Yes! You can find the perimeter of any shape by adding up all the sides. It doesn't matter if it's a square, rectangle, triangle, or any other shape.
Why do we need to know perimeter?
Knowing perimeter helps us in many real-life situations like planning gardens, building fences, designing safe zones, or even just understanding how far you've walked around a park or playground.
How is perimeter different from area?
Perimeter is the distance around the outside of a shape, while area is the space inside the shape. Think of perimeter like a fence around a garden, and area like how much grass is in the garden.