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Maths Adventures

Zoo maths quest: perimeter

A story-led junior maths adventure using animal counts, feeding plans and habitat maps 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, like measuring the fence around a zoo animal's habitat.

Learning outcome

By the end of this page, you will be able to measure the perimeter of simple shapes by counting the sides or adding up the lengths of all edges. Success signs:
  • You can find the perimeter of a rectangle or square by adding all the sides
  • You understand that perimeter is the distance around the outside of a shape
  • You can measure a shape and work out how much fencing you need
  • You can use a ruler or measuring tape to find the length of each side

Why this matters

Perimeter helps us know how much fencing or material we need to go around a shape. In real life, this is important for building fences, planning gardens, designing playgrounds, and making sure animals have enough space in their habitats. When you're helping plan a zoo, you need to know how much fencing to buy for each animal's home.

How it works

To find the perimeter of a shape:
  1. Look at all the sides of the shape
  2. Measure or count each side
  3. Add up all the side lengths
  4. The total is the perimeter
For example, if a rectangle has sides that are 4 metres, 6 metres, 4 metres, and 6 metres, you add them up: 4 + 6 + 4 + 6 = 20 metres

Examples you can see

Let's imagine you're helping plan the new home for a giraffe at the zoo. Example 1: Square Giraffe Habitat A square habitat has sides of 5 metres each.
  • Side 1: 5 metres
  • Side 2: 5 metres
  • Side 3: 5 metres
  • Side 4: 5 metres
Add them up: 5 + 5 + 5 + 5 = 20 metres The perimeter is 20 metres. Example 2: Rectangular Monkey Enclosure A rectangle has sides of 8 metres, 4 metres, 8 metres, and 4 metres.
  • Side 1: 8 metres
  • Side 2: 4 metres
  • Side 3: 8 metres
  • Side 4: 4 metres
Add them up: 8 + 4 + 8 + 4 = 24 metres The perimeter is 24 metres. Example 3: Triangle Zebra Enclosure A triangle has sides of 6 metres, 6 metres, and 6 metres.
  • Side 1: 6 metres
  • Side 2: 6 metres
  • Side 3: 6 metres
Add them up: 6 + 6 + 6 = 18 metres The perimeter is 18 metres.

Try it as a mini adventure

Zoo Maths Quest: The Great Fence Challenge You are the zookeeper's helper, and you need to build a fence around the new penguin habitat. The penguin area is a rectangle that is 10 metres long and 5 metres wide.
  1. First time: Measure the sides of the penguin habitat
  2. Second time: Add up the lengths of all sides
  3. Third time: Calculate how many metres of fence you need
  4. Fourth time: Draw a simple sketch of the penguin area with all measurements
  5. Fifth time: Check if you have the right number of fence posts (one at each corner)
If the penguin area is 10 metres long and 5 metres wide, then:
  • Two sides are 10 metres
  • Two sides are 5 metres
Add them up: 10 + 5 + 10 + 5 = 30 metres You need 30 metres of fencing.

Common mistakes

  • Mistake: Forgetting to add all the sides
    Why it happens: Children may only add the length and width, not all four sides.
    Fix: Always count all sides and add them up, even if some are the same length.
  • Mistake: Confusing perimeter with area
    Why it happens: Children may think perimeter is about covering the inside of a shape.
    Fix: Remember perimeter is the distance around the outside of a shape.
  • Mistake: Measuring the wrong sides
    Why it happens: Children may measure the inside of a shape or measure the same side twice.
    Fix: Make sure you measure each side once and only once.

Parent and carer guide

As a parent or carer, you can help your child by:
  • Using everyday objects like books, boxes, or toys to make shapes and measure the perimeter
  • Letting your child draw the shapes and label the sides
  • Encouraging them to count each side carefully
  • Using a ruler or measuring tape to check their measurements
  • Playing games like "how many steps around the room" to make it fun
What to say: "Let's measure each side of this shape and add them all up to find the perimeter." "Remember, perimeter is about the outside edge of the shape." "You can use your hands to trace around the shape to help you count each side." What not to worry about: It's normal for children to sometimes mix up perimeter and area. This is a common learning point and will improve with practice.

Practice questions

  1. What is the perimeter of a square with sides of 3 metres?
  2. What is the perimeter of a rectangle with sides of 7 metres, 4 metres, 7 metres, and 4 metres?
  3. What is the perimeter of a triangle with sides of 5 metres, 5 metres, and 5 metres?
  4. What is the perimeter of a rectangle with sides of 9 metres, 3 metres, 9 metres, and 3 metres?
  5. What is the perimeter of a square with sides of 6 metres?
Answers:
  1. 3 + 3 + 3 + 3 = 12 metres
  2. 7 + 4 + 7 + 4 = 22 metres
  3. 5 + 5 + 5 = 15 metres
  4. 9 + 3 + 9 + 3 = 24 metres
  5. 6 + 6 + 6 + 6 = 24 metres

FAQ

What is perimeter?

Perimeter is the total distance around the edge of a shape. It's like walking all the way around the outside of a shape.

How do I find the perimeter of a rectangle?

Measure each side of the rectangle and add all the sides together. For example, if a rectangle is 6 metres long and 4 metres wide, the perimeter is 6 + 4 + 6 + 4 = 20 metres.

Do I need to measure all sides?

Yes, you need to measure each side of the shape and add them all up to find the perimeter.

Can I use a ruler to measure the sides?

Yes, you can use a ruler or measuring tape to measure each side of a shape.

Why is perimeter useful?

Perimeter helps us know how much material we need to go around a shape, like fencing for a garden or a fence around an animal's habitat.