Geo_Book_Answers

Answers to Exercises
CHAPTER 12 REVIEW
1. 0.8387
2. 0.9877
3. 28.6363
4. a
b ; c a
;
b c
8
5. ;
17
15
8
; 17
15
6. s; t; s
t
7. 33°
8. 86°
9. 71°
10. 1823 cm2 11. 15,116 cm3 12. Yes, the plan meets the act’s requirements. The
angle of ascent is approximately 4.3°.
13. approximately 52 km
14. approximately 7.3°
15. approximately 22 ft
16. approximately 6568 m
17. approximately 2973 km/h
18. 393 cm2 19. 30 cm
20. 78°
21. 105 cm
22. 51°
23. 759 cm2 24. approximately 25 cm
25. 72 cm2 26. approximately 15.7 cm
27. approximately 33.5 cm2 28. approximately 10.1 km/h at an approximate
bearing of 24.5°
29. False; an octahedron is a polyhedron with
eight faces.
30. false
31. true
32. true
142 ANSWERS TO EXERCISES
33. False; the ratio of their areas is m
34. true
35. false; tangent of T
36. true
37. true
38. true
39. true
40. False; the slope of line 2 is
m
41. false
42. B 43. C 44. A 45. D
46. B 47. B 48. A 49. B
50. C
54.
51. D 52. C 53. A
100
cm3 3
55. 28 cm3 56. 30.5 cm3 57. 33
58. (x, y) → (x 1, y 3)
59. w 48 cm, x 24 cm, y 28.5 cm
60. approximately 18 cm
61. (x 5) 2 (y 1) 2 9
62. Sample answer: Each interior angle in a regular
pentagon is 108°. Three angles would have a sum of
324°, or 36° short of 360, which would leave a gap.
Four angles would have a sum exceeding 360° and
hence create an overlap.
63. approximately 99.5 m
64. 30 ft
65. 4 cm
66.
B
A
D
C
66a. mABC 2 mABD
66b. Possible answers: BD is the perpendicular
bisector of AC. It is the angle bisector of ABC,it
is a median, and it divides ABC into two
congruent right triangles.
1 .
.
n2 2
length of leg opposite T
length of leg adjacent to T