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MathWorks 10 Workbook
7.2 THE SINE RATIO
7.3 THE COSINE RATIO
BUILD YOUR SKILLS, P. 298
BUILD YOUR SKILLS, P. 310
1. a) sin A ≈ 0.62
b) sin A ≈ 0.54
1. a) cos 23° = 0.9205
2. a) sin 10° = 0.1736
b) sin 48° = 0.7431
sin 67° = 0.9205
c) sin 62° = 0.8829 d) sin 77° = 0.9744
b) cos 83° = 0.1219
3. sin 90° = 1
sin 7° = 0.1219
Possible reasons will vary.
c) cos 45° = 0.7071
4. a) a ≈ 8.2 cm
sin 45° = 0.7071
b) x ≈ 3.8 cm
d) cos 37° = 0.7986
5. about 7 ft
sin 53° = 0.7986
2. a) x ≈ 8.2 cm
6. about 8.6 m
7. a) h ≈ 14.3 mm
c) x ≈ 8.6 cm
b) h ≈ 12.9 cm
b) x ≈ 1.7 cm
d) x ≈ 12.2 cm
3. about 5.4 m
8. approximately 5.3 m long
4. about 9.8 yards
9. about 22 m
5. about 6.2 m
10.about 404.5 m
6. about 14.1 m
11. approximately 203.9 m
7. about 11.6 m
12.about 1.9 m
8. about 502 km
PRACTISE YOUR NEW SKILLS, P. 306
PRACTISE YOUR NEW SKILLS, P. 315
1. a) sin A ≈ 0.6371
b) sin B ≈ 0.7191
1. a) x ≈ 3.6 cm
b) a ≈ 4.8 m
2. a) x ≈ 17.9 cm
b) y ≈ 12.5 cm
c) r ≈ 9.5 cm
d) ℓ ≈ 3.1 m
3. about 5.5 m
2. approximately 17.3 m
4. about 8.6 m
3. approximately 23.7 m
5. about 41.7 m
4. about 1.24 km
5. about 8.49 km
6. about 3.42 m
Answer Key
7.4 THE TANGENT RATIO
7. r ≈ 7.3 m
BUILD YOUR SKILLS, P. 320
q ≈ 4.9 m
1. a) x ≈ 9.5 m
∠Q = 42°
c) r ≈ 2.4 m
b) a ≈ 22.4 in
d) p ≈ 7.9 in
8.
2. about 412 m
20° 20°
3. about 2.1 m
PRACTISE YOUR NEW SKILLS, P. 321
17 cm
1. about 21 m
h = 16 cm
2. about 9 m
3. about 5.5 ft
4. about 141.1 m
5. about 12.9 ft
6. about 373 m
7.5 FINDING ANGLES AND SOLVING
RIGHT TRIANGLES
BUILD YOUR SKILLS, P. 325
1. a) D ≈ 33°
b) F ≈ 26°
c) G ≈ 67°
d) H ≈ 89°
2. ∠X ≈ 61°
3. about 62°
4. about 54°
5. about 38°
6. about 51°
70°
70°
11.6 cm
9. width: about 10.6 yards; total height of
building: about 4.9 yards.
10.a) ∠R ≈ 28°
∠S ≈ 62°
t ≈ 3.2 m
b) ℓ ≈ 6.6 cm
∠M ≈ 45°
∠L ≈ 45°
11. pole height: about 8 m; the cable is attached
about 16 m away from the pole.
12.a) a ≈ 23 cm
b) b ≈ 18 cm
c) c ≈ 16 cm
d) d ≈ 12 cm
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