1. S2B Chapter 10 Areas and Volumes

2. 2009 Chung Tai Educational Press. All rights reserved. © Formulae of Areas of Plane Figures Area of square Area of rectangle  b Area of triangle Area of parallelogram  bh Area of trapezium

3. 2009 Chung Tai Educational Press. All rights reserved. © Areas of Similar Figures 1 cm 2 cm Two similar figures are shown on the left, if the area of the figure in green is 10 cm 2, then area of the figure in purple

4. 2009 Chung Tai Educational Press. All rights reserved. © Circumferences of Circles Circle Diameter Circumference Centre Circumference    Diameter

5. 2009 Chung Tai Educational Press. All rights reserved. © Approximate Value of  Following are some common approximate values of  : 3.14 Pressing the key of a calculator

6. 2009 Chung Tai Educational Press. All rights reserved. © Areas of Circles Area of a circle   r 2, where r is the radius. r Radius = r AB D A C B r rr

7. 2009 Chung Tai Educational Press. All rights reserved. © D O C x Lengths of Arcs and Areas of Sectors Length of arc CD Area of sector COD

8. 2009 Chung Tai Educational Press. All rights reserved. © Prisms and Cylinders

9. 2009 Chung Tai Educational Press. All rights reserved. © Volumes of Prisms and Cylinders Volume of prism / cylinder  Ah Volume of cylinder   r 2 h A h r h A h

10. 2009 Chung Tai Educational Press. All rights reserved. © How do you find the total surface area of the Total Surface Areas of Prisms Total surface area of the cuboid  2(lb  bh  lh) l b h lhlh lhlh bhbhbhbh lblb lblb The total surface area of a prism is the area of its net.

11. 2009 Chung Tai Educational Press. All rights reserved. © Total surface area of a cylinder  2  r 2  2  rh Total Surface Areas of Cylinders 2r2r h r r How do you find the total surface area of a cylinder? r h

12. 2009 Chung Tai Educational Press. All rights reserved. © Accumulation of Errors All values obtained by measurement are approximate values. There are errors in approximate values. Using measured values with errors for calculation will end up with errors in the results.

13. 2009 Chung Tai Educational Press. All rights reserved. © Accumulation of Errors The length and the width of a rectangle are measured 5 m and 4 m respectively, correct to the nearest m. Find the possible range of the area of the rectangle. 4 m 5 m Upper limit of the area  5.5  4.5 m 2  24.75 m 2 Lower limit of the area  4.5  3.5 m 2  15.75 m 2  15.75 m 2  Area < 24.75 m 2

14. The End