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Maths Adventures

Dragon maths quest: perimeter

A story-led junior maths adventure using hoards, scales and fiery puzzles to measure fences, walls and safe zones around places.

Quick answer

Perimeter is the total distance around the edge of a shape. You measure it by adding up all the sides.

Learning outcome

By the end of this page, you will know how to measure the perimeter of any shape by adding up all the sides, and you will understand why it's useful for planning safe zones, building fences, or solving dragon puzzles. Success signs:
  • You can identify all the sides of a shape
  • You can add up the sides to find the total distance
  • You can explain why perimeter matters in real life
  • You can solve a simple dragon maths quest using perimeter

Why this matters

Perimeter helps you know how much fencing you need for a garden, how far you run around a playground, or how much rope to make a safe zone for your dragon's treasure. It's useful in games, building, cooking, and even in treasure hunts! When you understand perimeter, you're ready to solve puzzles, plan spaces, and become a maths master.

How it works

To find the perimeter of any shape:
  1. Look at all the sides of the shape
  2. Measure each side (or count the units if it's on a grid)
  3. Add all the sides together
For example, if you have a rectangle with sides of 5 cm, 3 cm, 5 cm, and 3 cm: 5 + 3 + 5 + 3 = 16 cm

Examples you can see

Let's imagine you're helping a dragon named Sparky who wants to build a fence around his treasure hoard. Sparky has a rectangular area that is 6 metres long and 4 metres wide.
  1. First, we look at the shape. It's a rectangle, so it has 4 sides
  2. Two sides are 6 metres long (the length)
  3. Two sides are 4 metres wide (the width)
  4. Now we add them up: 6 + 4 + 6 + 4 = 20 metres
So Sparky needs 20 metres of fence to protect his treasure! Here's a square treasure chest that is 3 metres on each side:
  1. Four sides, each 3 metres
  2. 3 + 3 + 3 + 3 = 12 metres

Try it as a mini adventure

Dragon Maths Quest: The Treasure Fence You are a young explorer helping Sparky the dragon protect his treasure. Sparky's treasure is in a rectangular area that is 8 metres long and 5 metres wide.
  1. First, you need to find the perimeter of the treasure area
  2. How many metres of fence do you need to build around it?
  3. Draw your own rectangle and label the sides
  4. Count the metres around the outside
  5. 4th time: You need to build a path around the fence that is 1 metre wide. How much extra fencing do you need?
Try this with your parent or friend:
  • Use a ruler or measuring tape to measure the sides of a book or table
  • Count how many steps it takes to walk around your room
  • Draw a shape on paper and measure each side

Common mistakes

  • Mistake: Forgetting to measure all sides
    Why it happens: When shapes look similar, children may miss a side or count the same side twice
    Fix: Trace around the shape with your finger or a pencil to make sure you count each side once
  • Mistake: Adding the length and width only
    Why it happens: Children think that to find perimeter, you just add the two different measurements
    Fix: Remember that perimeter is the total around the shape - you must add all sides
  • Mistake: Confusing perimeter with area
    Why it happens: Both involve measuring shapes, so children mix them up
    Fix: Perimeter is the distance around, area is the space inside

Parent and carer guide

To help your child with perimeter:
  • Point out real-world examples like garden fences, swimming pools, or rooms at home
  • Use a measuring tape or ruler to measure different sides of objects
  • Ask your child to find the perimeter of a book, a picture frame, or a table
  • Encourage drawing shapes and labelling the sides
  • Practice counting around shapes together
  • Don't worry if they make mistakes - they're learning!

Practice questions

  1. What is the perimeter of a rectangle with sides 7 cm, 4 cm, 7 cm, and 4 cm?
  2. A square has sides of 5 metres. What is its perimeter?
  3. Find the perimeter of a triangle with sides 3 m, 4 m, and 5 m
  4. A garden is 10 metres long and 6 metres wide. What is the perimeter?
  5. What is the perimeter of a rectangle with sides 12 cm, 8 cm, 12 cm, and 8 cm?
Answers:
  1. 7 + 4 + 7 + 4 = 22 cm
  2. 5 + 5 + 5 + 5 = 20 metres
  3. 3 + 4 + 5 = 12 metres
  4. 10 + 6 + 10 + 6 = 32 metres
  5. 12 + 8 + 12 + 8 = 40 cm

FAQ

What is perimeter?

Perimeter is the total distance around the edge of a shape. You measure it by adding up all the sides.

How do you find the perimeter of a square?

Since all sides of a square are equal, you can multiply one side by 4. For example, a square with sides of 6 cm has a perimeter of 6 × 4 = 24 cm.

Can you find perimeter without measuring?

Yes! If a shape is drawn on grid paper, you can count the squares along the edges to find the perimeter.

Why do we need to know perimeter?

Perimeter helps us plan spaces, know how much fencing we need, or measure safe zones. It's useful in building, gardening, and even in games and treasure hunts.

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. For example, a rectangle's perimeter is the sum of all sides, while its area is length times width.