AREA AND VOLUME Form 1 Mathematics Chapter 7

Reminder Lesson requirement Before lessons start Textbook 1B Workbook 1B Notebook Folder Before lessons start Desks in good order! No rubbish around! No toilets!

Result of CBQ (Ch. 9) Result of Close Book Quiz Major Problems Full mark: 40 and 10 bonus Highest: 44 Lowest: 10 Average: 23.8 Number of students between 10 – 19: 13 Number of students between 0 – 9: 0 Major Problems Cannot get the drawing in rotation Cannot get the coordinates in transformation Mix up the rotation and reflection

Result of CBQ (Ch. 9) Result of Close Book Quiz 9th place: KO Ka Chung Boston LIN Long Chak, Vincent 8th place: FU Ling Yin, Larry 7th place: LAU Cheuk Hei, Anson 6th place: CHEN Yi, David 5th place: CHAN Tsz Long, Sam 4th place: YUEN Tin Wai, Timmy 2nd place: LI Ming Chun, Edward WU SHAN Hao Yi 1st place LI Sai Kong Congratulations!!!!!! Well done!!!!!!

Area of plane figures (p.2) 1. Area of triangle =  base  height 1 2 2. Area of square = length  length 3. Area of rectangle = length  width

Area of plane figures (p.2) 4. Area of parallelogram = base  height 5. Area of trapezium =  sum of lengths of parallel sides  height 1 2

Calculating areas (p.3) Splitting Method Filling Method Area of the figure 1 2 = 3  3 + (3 + 6)  2 cm2 = 18 cm2 Area of the figure = 10  4 –  2  2 cm2 1 2 = 38 cm2

Time for Practice Pages 10 – 11 of Textbook 1B Questions 5 – 18 Pages 1 – 3 of Workbook 1B Questions 1 – 5

WORKBOOK

WORKBOOK 16 36 10 260 cm2 36 36 10 (18  26) cm2 = 468 cm2 260 468 728 cm2

WORKBOOK 3 3 18 cm2 728 18 710 cm2

Volume of Simple Solids (p.3) 1. Volume of cube = length  length  length 2. Volume of cuboid = length  width  height

PRISMS (柱體, P.12) A solid with uniform cross- section in the shape of a polygon is called a prism. A prism is named and classified according to the shape of its base. The perpendicular distance between the two parallel bases of a prism is called its height (or length). The faces (other than the two bases) of a prism are called lateral faces. base height lateral faces base Triangular prism

Volume of Prisms (p.17) Volume = area of base  height e.g. Volume of the solid = 260  20 cm3 = 5200 cm3

Surface Areas of Prisms (p.14) Total surface area = areas of the two bases + total area of all lateral faces e.g. Total surface area of the solid = [2  260 + 6  (20  10)] cm2 = 1720 cm2

Volume of Prisms Volume of the triangular prism = ? Area of the base of the prism = ( 7  4  2 ) cm2 = 14 cm2 So, the volume = ( 14  10 ) cm3 = 140 cm3

Volume of Prisms Volume of the rectangular prism (cuboid) = ? The volume = [ ( 5  3 )  6 ] cm3 = 90 cm3 = [ ( 3  6 )  5 ] cm3 = [ ( 5  6 )  3 ] cm3

Volume of Prisms Find the volume of the prism. Area of base = (12  7 – 8  5) cm2 = 44 cm2 = 44  11 cm3 = 484 cm3

Volume & Surface Area of Prisms The figure shows a gold ingot in the shape of a prism. Its base is a trapezium, and the other faces are rectangles. If the volume of the gold ingot is 540 cm3, find (a) the value of d, (b) the total surface area of the gold ingot. 1 2 = (6 + 12)  4 cm2 (a) Area of trapezium ∴ The volume of the gold ingot i.e. 36d = 540 d = 15 (b) Total surface area of the gold ingot = [2  36 + 2  (15  5) + 15  12 + 15  6] cm2 = 492 cm2 = 36 cm2 = 36d cm3

Time for Practice Pages 22 – 23 of Textbook 1B Questions 10 – 20 Pages 6 – 7 of Workbook 1B Questions 3 – 6

WORKBOOK

WORKBOOK 8 8 8 512 5 10 4 200 cm3 200 12d 512 4 3 d 12d = 312 12d cm3 26

WORKBOOK 2.5 1 6 15 cm2 19 15 4 cm2 4 2 cm2 2 2.5 5 cm3 1 2 3 6 cm3 6 cm3 5 cm3 B

Reminder Missing Homework, Re-do Homework SHW (I) SHW (II) Today! SHW (I) SHW (II) 22 Mar (Fri) Open Book Quiz Close Book Quiz 26 Mar (Tue)

Enjoy the world of Mathematics! Ronald HUI