MEP: Demonstration Project
Y9B, Unit 15
ACTIVITIES 15.1 - 15.5
Notes and Solutions
Notes and solutions given only where appropriate.
15.1 1.
2.9 cm, 8.5 cm
sin 20 ° = 0.34
cos 20 ° = 0.94
tan 20 ° = 0.36
2.
15.3 1.
2.
(a)
Angle
sin
cos
tan
20 °
0.34
0.94
0.36
30 °
0.50
0.87
0.58
40 °
0.64
0.77
0.84
50 °
0.77
0.64
1.19
60 °
0.87
0.50
1.73
70 °
0.94
0.34
2.75
45 °, 45 °, 90 °
(b)
2 cm
(c)
sin 45 ° =
(a)
30 °, 60 °, 90 °
(b)
BC = 1, AB = 3
(c)
sin 60 ° =
3
1
, cos 60 ° = , tan 60 ° = 3
2
2
(d)
sin 30 ° =
1
3
1
, cos 30 ° =
, tan 30 ° =
2
2
3
1
,
2
cos 45 ° =
1
,
2
15.4 1.
θ = 7.1 °,
15.5 1.
2.
36 km
(a)
78 km
(c) 26 km
Extension 32 km, 0857 hours
tan 45 ° = 1
θ = 14.8 °
© The Gatsby Charitable Foundation
(d)
0943 hours ; 80 km
MEP: Demonstration Project
ACTIVITY 15.6
15.6
© The Gatsby Charitable Foundation
Y9B, Unit 15
Notes and Solutions