Calculating the perimeter of different shapes is something we learned in Year 7.

Once you understand it, it’s actually pretty easy. Let’s dive into it so it feels less tricky!

What is Perimeter?

First, perimeter is the total distance around the outside of a shape.

Think about walking around your school playground. The distance you walk is what we call the perimeter! You find it by adding up the lengths of all the sides.

How to Calculate Perimeter for Basic Shapes

Here’s how to find the perimeter for some common shapes:

1. Rectangle

   • To find the perimeter of a rectangle, you use this formula: P = 2 × (length + width)
   • For example, if the length is 5 meters and the width is 3 meters, the perimeter would be: P = 2 × (5 + 3) = 2 × 8 = 16 meters

2. Square

   • All sides of a square are the same, so finding the perimeter is easier: P = 4 × side
   • If each side is 4 meters, then: P = 4 × 4 = 16 meters

3. Triangle

   • To find the perimeter of a triangle, add up the lengths of all three sides: P = side_1 + side_2 + side_3
   • If the sides are 3 meters, 4 meters, and 5 meters, then: P = 3 + 4 + 5 = 12 meters

4. Circle (Circumference)

   • This one is a bit different because it’s round! The perimeter of a circle is called the circumference, found using: C = 2 × π × radius
   • If the radius is 3 meters, it would be: C ≈ 2 × 3.14 × 3 ≈ 18.84 meters

Helpful Tips for Calculating Perimeter

• Draw It Out: When solving problems, sketching the shape can really help. It makes it easier to see which measurements you need.

• Keep Units the Same: Make sure all your measurements are in the same units, like all in meters or all in centimeters. It’s easy to forget this, but it’s important for getting the right answer!

• Practice with Real-Life Examples: Try measuring things around your house, like your garden or a room. This helps you use what you’ve learned and makes it more fun!

Conclusion

So that’s it! The perimeter is just a way to measure the edges of a shape.

For rectangles and squares, you add up the sides, and for circles, you use the radius.

Once you understand the formulas and practice a bit, it won’t seem so scary. Just remember to double-check your work, and soon, you’ll be great at finding the perimeter of anything! Happy measuring!