1. Angles of Elevation and Depression
GEOMETRY LESSON 9-3
Pages Exercises
of elevation from sub to boat
of depression from boat to sub
3.  of elevation from boat to lighthouse
of depression from lighthouse to boat
of elevation from Jim to waterfall
of elevation from Kelley to waterfall
of depression from waterfall to Jim
of depression from waterfall to Kelley ft m m ft
13. about 986 m ft m yd km ft
19. 64° °
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2. Angles of Elevation and Depression
GEOMETRY LESSON 9-3
21. about 194 m
22. a-b Check students’ work. m
24. 72, 72
25. 46, 46
26. 27, 27
27. 20, 20
28. a. 560 ft
28. (continued)
b. about 15.9°
29. a. Length of any guy wire = dist. on the ground from tower to the guy wire div. by the cosine of the formed by the guy wire and the ground.
29. (continued)
b. Height of attachment = dist. on the ground from tower to the guy wire times the tangent of the formed by the guy wire and the ground.
30. 5
31. about 2.8
; about 84.9
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3. Angles of Elevation and Depression
GEOMETRY LESSON 9-3 m
34. about 28 ft
35. Measure the length of the stick and the shortest shadow. The tangent of the angle of elevation is the ratio of the length of the stick to the length of the shadow. Then use inverse tangent.
36. Check students’ work.
37. C
38. F
39. B
40. A
41. C
42. A
43. C
44. [2] a.
b. Let h represent the height of the tree.
h ≈ tan 83º
h ≈ (8.14)
≈ = 104
The tree is about
104 ft tall.
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4. Angles of Elevation and Depression
GEOMETRY LESSON 9-3
44. [1] correct drawing OR correct solution without work shown m ft
47. 45
48. 70
50. 60
54. x = 9; 60, 30, 40, 30
55. y = 3, x = 2; 16, 10, 10, 16
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