year 8 maths

152 Chapter 3 Measurement and Pythagoras’ theorem
3 How many rectangular faces are on these solids?
a triangular prism b rectangular prism
c hexagonal prism d pentagonal prism
Pentagonal prism
Example 15
4 Find the surface area of these prisms.
a
b
c
2 cm
8.2 m
2 cm
1 cm
3 cm
d
5 m
f
9 cm
12 cm
8 cm
12 cm
4 cm e 4 m
3 m
6 m
15 cm
14 cm
g
6 mm
h
i
1.5 m
4 mm
6 mm
8 m
4.2 m
3 m
5 mm
5 This prism has two end faces that are parallelograms.
a Use A = bh to find the combined area of the
two ends.
b Find the surface area of the prism.
2 cm 1.5 cm
6 cm
8 cm
PROBLEM-SOLVING AND REASONING
6, 7, 10 6–8, 10, 11
7–11
6 An open box (with no lid) is in the shape of a cube and is painted on the outside including the
base. What surface area is painted if the side length of the box is 20 cm ?
7 A book measuring 20 cm long, 15 cm wide and 3 cm thick is covered in plastic. What area of
plastic is needed to cover 1000 books? Convert your answer to m 2 .
Cambridge Maths NSW
Stage 4 Year 8 Second edition
ISBN 978-1-108-46627-1 © Palmer et al. 2018
Cambridge University Press
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