Exploring Perimeter with Fun Shapes

Year 8 Mathematics Key Stage 3 Learning about perimeter through visual examples

What is Perimeter?

Perimeter is the distance around the outside of a shape Think of it like walking around the edge We measure it in units like centimetres (cm) or metres (m) Every shape has a perimeter

Finding Perimeter of a Square

A square has 4 equal sides To find perimeter: add all 4 sides together Example: If each side is 3cm, perimeter = 3 + 3 + 3 + 3 = 12cm Quick way: multiply one side by 4

Let's Practice with Squares!

Look at the square on the screen Each side is 5cm Work with your partner Add up all four sides to find the perimeter

Finding Perimeter of a Rectangle

A rectangle has 4 sides: 2 long sides and 2 short sides The long sides are equal to each other The short sides are equal to each other Add all 4 sides: long + long + short + short

Quick Check!

Look at this rectangle: Length = 8cm, Width = 3cm What is the perimeter? Talk to your neighbor and work it out together!

Real-Life Examples

Football pitch - we walk around the edge Picture frame - we measure around the outside Garden fence - goes around the whole garden School playground - the perimeter is the boundary

Triangle Perimeter

{"left":"A triangle has 3 sides\nAll sides can be different lengths","right":"Add all 3 sides together\nExample: 4cm + 5cm + 6cm = 15cm"}

Perimeter Detective Challenge

Hands-On Measuring

Use your ruler to measure objects Find 3 rectangular objects in the classroom Measure the length and width Calculate the perimeter of each object

Challenge Question

A rectangular garden is 10m long and 6m wide The owner wants to put a fence all around it How much fencing does he need? Remember: this is asking for the perimeter!

What We've Learned Today

Perimeter is the distance around a shape Square perimeter = add 4 equal sides Rectangle perimeter = add 2 long + 2 short sides Triangle perimeter = add all 3 sides We can find perimeter of real objects too!