year 8 maths

610
5 a 30 mm b 610 cm c 8930 m d 3000 mm
e 2.1 m f 32 cm g 9.62 km h 0.38 km
i 4.3 mm j 2040 cm k 23.098 m l 3.42 km
m 194.3 m n 0.01 km o 24.03 mm p 0.994 km
6 a 19 m b 44 m c 13 cm
d 32 cm e 28 km f 18 cm
g 17.2 mm h 34.4 cm i 29.4 m
7 a 5 b 2 c 4 d 18
e 9.5 f 6.5
8 a 40 cm b 17 cm c 7.8 cm d 2000 cm
e 46 cm
f 17 600 cm
9 a 2 b 3 c 9
10 $2392
11 8 min
12 240 cm
13 a P = 2a + b b P = 2a + 2b
c P = 2a + 2b
e P = 8a + 2b
d P = 2a + 2b
f P = 4a + 2b
14 a x = P − 11 b x = P − 4 c x = P − 3
2
d x = P − 8
2
e x = P 4
15 a 6 squares b 8 squares
Exercise 3B
f x = P 8
1 a 15.71 b 40.84 c 18.85 d 232.48
2 a 3.1 b 3.14 c 3.142
3 a diameter b radius c circumference
4 Answer is close to pi.
5 a 12.57 mm b 113.10 m c 245.04 cm
d 12.57 m e 21.99 km f 15.71 cm
6 a 314 cm b 62.8 m c 18.84 km
7 a 44 mm b 132 cm c 220 m
8 11.0 m
9 12 566 m
10 a 64.27 cm b 12.34 m c 61.70 mm
11 a 28.57 cm b 93.97 m c 5.57 cm
12 a 25.13 cm b 56.55 m c 35.71 m
13 Svenya and Andre
14 d = 2r, so 2πr is the same as πd.
15 a 4π mm b 36π m c 78π cm
d 4π m e 7π km f 5π cm
16 a 8π cm b 18π m c (5π + 20) m
17 a i r = C 2π
ii d = C π
b i 2.23 m ii 6.37 cm
Exercise 3C
1 a i 100 ii 400 iii 3
b i 10 000 ii 70 000 iii 4
c i 1 000 000 ii 5 000 000 iii 2.5
d i 10 000 ii 30 000 iii 7.5
Cambridge Maths NSW
Stage 4 Year 8 Second edition
2 a 7 m, 3 m b 8 cm, 6 cm (or other way around)
c 2.4 mm, 1.7 mm
3 10 000
4 a 200 mm 2 b 70 000 cm 2 c 500 000 m 2
d 30 000 m 2 e 34 mm 2 f 0.07 m 2
g 30.9 cm 2 h 4000 m 2 i 0.2 m 2
j 0.45 km 2 k 0.4 ha l 32.1 cm 2
m 32 ha n 51 cm 2 o 4.3 mm 2
p 0.4802 m 2 q 1.904 ha r 0.2933 ha
s 49 m 2 t 7700 m 2 u 24 000 m 2
5 a 9 cm 2 b 21 m 2 c 39 cm 2
d 18 cm 2 e 33 m 2 f 144 mm 2
g 63 m 2 h 3 m 2 i 6 km 2
6 a 70 m 2 b 54 m 2 c 140 cm 2
d 91 cm 2 e 46 km 2 f 64 mm 2
7 a 200 000 mm 2 b 430 000 cm 2 c 0.0000374 km 2
d 0.01092 m 2 e 20 cm 2 f 600 ha
8 a 45 cm 2 b 168 m 2 c 120 km 2
9 a 6 m b 1.5 cm
10 a 25 m 2 b 20.25 cm 2 c 28 cm d 52 m
11 10 cm 12 $48
13 a A = 4b 2 + ab or A = b(4b + a)
b A = 1.5ab or A = 3ab
2
c A = a 2 − ab
2 or A = a ( a − b 2)
14 a 4 b 1
15 a b = A b l = √A c h = 2A
l
b
16 a i 2.59 km 2 ii 2589988 m 2 iii 259 ha
iv 4047 m 2 v 0.4 ha vi 2.5 acres
b 81 ha
c 62%
Exercise 3D
1 a 6 b 30 c 13.5 d 33
2 a 90° b height
c perpendicular
e rhombus, kite
d parallel, perpendicular
3 a parallelogram, 50 m 2 b parallelogram, 4.5 cm 2
c parallelogram, 6 m 2 d rhombus, 7.5 cm 2
e rhombus, 121 km 2 f rhombus, 9.61 m 2
g kite, 4 cm 2 h kite, 300 mm 2
i kite, 0.9 mm 2 j trapezium, 96 cm 2
k trapezium, 32.5 m 2 l trapezium, 560 mm 2
4 a 6 cm 2 b 35 m 2 c 84.5 cm 2
5 0.27 m 2
6 2 m
7 $1160
8 3 cm and 9 cm
9 a trapezium b 19.5 cm 2
10 a A = 2x 2 b A = 3ab c A = 8a 2
11 No, use formula for parallelogram A = bh, as we already
know these lengths.
ISBN 978-1-108-46627-1 © Palmer et al. 2018
Cambridge University Press
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