1.1 Calculate perimeter and area of triangles & rectangles

Tell me two truths and a lie about yourself!
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Slide 1: Mind map
MathematicsLower Secondary (Key Stage 3)

This lesson contains 33 slides, with interactive quizzes and text slides.

time-iconLesson duration is: 60 min

Items in this lesson

Tell me two truths and a lie about yourself!

Slide 1 - Mind map

Calculate perimeter and area of triangles & rectangles

Slide 2 - Slide

What is a triangle?

Slide 3 - Mind map

Triangle: a definition
A triangle is a closed, 2-dimensional shape with 3 sides, 3 angles, and 3 vertices. A triangle is also a polygon.

Slide 4 - Slide

What is a rectangle?

Slide 5 - Mind map

Rectangle: a definition
A rectangle is a 2D shape that has 4 sides, 4 corners, and 4 right angles. Opposite sides of a rectangle shape are the same length, with one pair being longer than the other pair. If all the sides of a rectangle were the same size, it would be known as a square.

Slide 6 - Slide

What is the perimeter of a shape?

Slide 7 - Mind map

Perimeter: a definition
The perimeter is the distance around the edge of a shape. 

Slide 8 - Slide

What is the area of a shape?

Slide 9 - Mind map

Area: a definition
The total space taken up by a flat (2-D) surface or shape of an object. 

Slide 10 - Slide

Perimeter: Introduction

Slide 11 - Slide

You will need:
  • Clip board
  • Pencil
  • Squared paper
  • a device with a camera
  • 30cm Ruler, metre ruler, tape measure/trundle wheel
  • A maths partner

Slide 12 - Slide

  • find 5 triangles
  • find 5 rectangles
  • sketch the triangles and rectangles
  • label the perimeter of the sketches with your measurements
  • find small, medium and large triangles and rectangles
  • use the ruler, metre stick, trundle wheel and tape measure
  • photograph each triangle and rectangle

Slide 13 - Slide

Triangle and rectangle scavenger hunt

Slide 14 - Slide

See you in 15 minutes!

Slide 15 - Slide

What was the largest perimeter of a rectangle that you found?

Slide 16 - Mind map

What was the smallest perimeter of a triangle you found?

Slide 17 - Mind map

Use this to drag the screen around
Use this to zoom in and out in order to see more/less detail
Connection line
Use this to connect the question with your answer - use a sticky note to add your answer. Don't forget to add your name to the sticky note!
Choose a question to answer
Miro Board

Slide 18 - Slide

Success will lok like this!

Slide 19 - Slide

Perimeter and Area

Slide 22 - Slide

Finding the area of your rectangles!

Slide 23 - Slide

What is the area of your largest rectangle? Show your working out!

Slide 24 - Open question

Area of a triangle

Slide 26 - Slide

What is the area of your smallest triangle? Show your working out.

Slide 27 - Open question

Explain how you find the area of a rectangle using only words.

Slide 30 - Open question

Explain how you find the area of a triangle using only words

Slide 31 - Open question

I don't fully understand this yet...

Slide 32 - Mind map

I feel very confident about...

Slide 33 - Mind map