1. Ratios and Proportions
GEOMETRY LESSON 8-1
Pages Exercises
1. 1 : 1000
2. 1 : 370
3–11. Answers may vary. Samples are given.
3. 3b 4. 5. 6. 4 3 b a 7.
8. 4a 9.
10.
11.
12. 4
13. 1
14. 4 7
b + 4 2
19. 14
20. 7 mi
22. about 75 mi
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2. Ratios and Proportions
GEOMETRY LESSON 8-1
23. about 135 mi
24. about 67.5 mi
in. by 22.5 in.
: 6
27. 5 : 4
28. 4 : 3
29.
30.
31.
32.
33.
34. Check students’ work.
35. 6
36. 32
38. 6
39. 4
40.
41. 7
42. cm
in.
45. 9; 18
46. 9; 12
47. 8; 21 5 48 7 3 9 4 30 18 b 2 12 19 25
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3. Ratios and Proportions
GEOMETRY LESSON 8-1
48–51. Answers may vary. Samples are given.
48.
49.
50.
51.
52. Elaine did not convert units, and thought the ratios equaled 1.
53. or
54. or
55. b d a c
c + 2d
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4. Ratios and Proportions
GEOMETRY LESSON 8-1 a b c d
= (Given); ad = bc (Cross-Product Prop.); bc = ad (Symm. Prop. of =); = (Div. Prop. of =); = (Simplify)
= (Given); ad = bc (Cross-Prod. Prop.); = (Div. Prop. of =); = (Simplify)
= (Given); = (Add. Prop. of =);
+ = (Subst.); = (Simplify)
59. x = 5; y = 24
60. x = 3; y = 15
61. x = 3; y = 21
62. C
63. G
64. D
65. H
66. [2] a =
(OR equivalent proportion)
b. 135 km bc ac ad ac b a d c a b c d ad cd bc cd a c b d a b c d a b c d
2.75 16
23.2 x a b b c d d
a + b b
c + d d
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5. Ratios and Proportions
GEOMETRY LESSON 8-1
66. (continued)
[1] incorrect proportion OR incorrect distance
67.
60%
68. 25%
69.
parallelogram
72.
rhombus, parallelogram
73. I and III
74. II and III
75. a. If an is not acute, then it does not measure between 0 and 90.
70.
trapezoid
71.
rectangle, parallelogram
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6. Ratios and Proportions
GEOMETRY LESSON 8-1
75. (continued)
b. If an does not measure between 0 and 90, then it is not acute.
76. a. If two lines are not ||, then they are not coplanar.
b. If two lines are not coplanar, then they are not ||.
77. a. If two are not compl., then the are not both acute.
b. If two are not both acute, then they are not compl. s
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