Area - Revision

# Area - Revision

## Area - Revision

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##### Presentation Transcript

1. Area - Revision 1cm 1cm The area of a shape is simply defined by : “the amount of space a shape takes up.” Think of a square measuring 1 cm by 1cm we say it is : 1cm2 ( 1 square centimetre )

2. Area of a Rectangle Example Find the area of the rectangle B = 2cm L = 9cm Area = Length x Breadth A = L x B A = 9 x 2 A = 18 cm2

3. Area of a Rectangle Example B cm Find the length B of the rectangle opposite A = 36cm2 L = 12cm Area = Length x Breadth Balancing Method A = L x B 36 = 12 x B Remember units

4. 9cm 6cm 8cm 5cm Area of a Composite Calculate the area of this shape Total Area = 72 + 30 = 102cm2 A = l x b A = 9 x 8 A = l x b A = 72cm2 A = 6 x 5 A = 30cm2

5. 5cm 6cm Area of a Composite Calculate the area of this shape Rectangle 1 16cm A = l x b A = 16 x 5 5cm A = 80cm2 Rectangle 2 A = l x b Total Area A = 6 x 5 = 80 + 30 =110cm2 A = 30cm2

6. Any Triangle Area h = vertical height b Sometimes called the altitude h 6

7. Any Triangle Area 8cm Example 1 : Find the area of the triangle. 6cm 7

8. Any Triangle Area 4cm Example 2 : Find the area of the triangle. Altitude h outside triangle this time. 10cm

9. Parallelogram Area h b Important NOTE h = vertical height

10. Parallelogram Area Example 1 : Find the area of parallelogram. 3cm 9cm

11. Area of a Rhombus d D This part of the rhombus is half of the small rectangle.

12. Area of a Kite d D Exactly the same process as the rhombus

13. Rhombus and Kite Area Example 1 : Find the area of the shapes. 2cm 4cm 5cm 9cm

14. Trapezium Area a cm Two triangles WXY and WYZ X Y 1 h cm 2 Z W b cm

15. Trapezium Area Example 1 : Find the area of the trapezium. 5cm 4cm 6cm

16. The radius is measured from the centre of the circle to the edge. Circumference radius diameter The diameter is measured from one edge to the other passing through the centre of the circle. Parts of the Circle O O = centre of circle Radius = ½ x diameter Diameter = 2 x radius

17. Circle Investigation To calculate the circumference of a circle

18. Main part of a Circle Example : Find the length of the circumference (Perimeter) of each circle 2cm 10cm

19. Area of a Circle To find the area of a circle A = Πr² Where A = area r = radius

20. Area of a circle Solution Q.Find the area of the circle ? 4cm

21. Area of a circle Solution • The diameter of the circle is 60cm. • Find area of the circle?

22. Area of a Circle What have we learned so far