1. Finding theFinding the
Area of aArea of a
RectangleRectangle

2. Area of a RectangleArea of a Rectangle
ObjectivesObjectives
• To calculate areas ofTo calculate areas of
rectanglesrectangles
• To calculate areas ofTo calculate areas of
polygons made of rectanglespolygons made of rectangles

3. Area of a RectangleArea of a Rectangle
Area is the measure of how much spaceArea is the measure of how much space
a shape takes up. We measure it ina shape takes up. We measure it in
squares such as square centimetres orsquares such as square centimetres or
metres etc.metres etc.1 cm
1 cm
11 22 33 44 55 66 77
88 99 1010 1111 1212 1313 1414
1515 1616 1717 1818 1919 2020 2121
2222 2323 2424 2525 2626 2727 2828
This rectangleThis rectangle
takes up 28takes up 28
squares.squares.
It has an area ofIt has an area of
28 square28 square
centimetrescentimetres
28 cm28 cm22

4. Area of a RectangleArea of a Rectangle
It could take a long time to cover shapesIt could take a long time to cover shapes
in squares. Luckily there is an quickerin squares. Luckily there is an quicker
way.way.7 cm7 cm
4 cm4 cm
×× == 28 cm28 cm22

5. Area of a RectangleArea of a Rectangle
Use this formulae to find the area ofUse this formulae to find the area of
rectangles.rectangles.
Area of a rectangle = length × breadthArea of a rectangle = length × breadth
lengthlength
breadthbreadth

6. Area of a RectangleArea of a Rectangle
Can you find the areas of theseCan you find the areas of these
rectangles?rectangles?
5 cm5 cm
3 cm3 cm15 cm15 cm22
2 cm2 cm
7 cm7 cm
14 cm14 cm22
7 m7 m
7 m7 m49 m49 m22

7. Area of a RectangleArea of a Rectangle
Can you think of a way to find theCan you think of a way to find the
area of this shape?area of this shape?
12 cm12 cm
6 cm6 cm
5 cm5 cm
7 cm7 cm
3 cm3 cm

8. Area of a RectangleArea of a Rectangle
Split the shape into rectangles?Split the shape into rectangles?
12 cm12 cm
6 cm6 cm
5 cm5 cm
7 cm7 cm
3 cm3 cm

9. Area of a RectangleArea of a Rectangle
Find the area of each rectangle?Find the area of each rectangle?
6 cm6 cm
5 cm5 cm
7 cm7 cm
3 cm3 cm
5 × 6 = 30 cm5 × 6 = 30 cm22
7 × 3 = 21 cm7 × 3 = 21 cm22

10. Area of a RectangleArea of a Rectangle
Add the areas together to find the areaAdd the areas together to find the area
of the complete shape?of the complete shape?
30 + 21 = 51 cm30 + 21 = 51 cm22
30 cm30 cm22
21 cm21 cm22

11. Area of a RectangleArea of a Rectangle
Can you find the areas of these shapes?Can you find the areas of these shapes?
11 cm11 cm
5 cm5 cm
7 cm7 cm
4 cm4 cm
2 cm2 cm
43 cm43 cm22
6 m6 m
4 m4 m
3 m3 m
4 m4 m
1 m1 m
22 m22 m22

12. Area of a RectangleArea of a Rectangle
Here is a challenge can you work out theHere is a challenge can you work out the
area of this shape with a hole in it?area of this shape with a hole in it?
10 cm10 cm
5 cm5 cm
5 cm5 cm
2 cm2 cm
Clue: Take the area of the hole from the area of theClue: Take the area of the hole from the area of the
whole!whole!
50 cm50 cm22
– 10 cm– 10 cm22
= 40 cm= 40 cm22

13. Remember:Remember:
Area of a rectangle = length × breadthArea of a rectangle = length × breadth
lengthlength
breadthbreadth
Split more complicated shapes intoSplit more complicated shapes into
rectangles and find the area of eachrectangles and find the area of each
rectangle then add them together.rectangle then add them together.
Over to you.Over to you.