Pre-Algebra Chapter 9

Find each measure. Round to the nearest tenth.
37. 38. 39.
x ft
30˚
x ft
9 ft 22˚
30 ft
42˚
x ft
8 ft
Trigonometric ratios are
used to solve problems
about the height of
structures. Visit
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webquest to continue
work on your
WebQuest project.
Standardized
Test Practice
CRITICAL THINKING
For Exercises 40–42, refer
60˚ 2
1
45˚
2
1
to the 45°-45°-90° and
30°-60°-90° triangles shown.
45˚
30˚
40. Complete the table
shown. Round to four
1
3
decimal places, if
necessary.
41. Write a few sentences
describing the similarities
among the resulting
sine and cosine values.
x
sin x
cos x
tan x
30° 45° 60°
42. Which angle measure has the same sine and cosine ratio?
43. WRITING IN MATH Answer the question that was posed at the beginning
of the lesson.
How are ratios in right triangles used in the real world?
Include the following in your answer:
• an explanation of two different methods for finding the measures of the
lengths of the sides of a right triangle, and
• a drawing of a real-world situation that involves the sine ratio, with the
calculations and solution included.
44. If the measure of the hypotenuse of a right triangle is 5 feet and
mB 58, what is the measure of the leg adjacent to B?
A 4.2402 B 8.0017 C 0.1060 D 2.6496
45. Find the value of tan P to the
nearest tenth.
A 2.6 B 0.5
C 0.4 D 0.1
8 cm
M
N
20˚
21 cm
P
Maintain Your Skills
Mixed Review
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46. At the same time a 40-foot silo casts a 22-foot shadow, a fence casts a
3.3-foot shadow. Find the height of the fence. (Lesson 9-7)
The coordinates of the endpoints of a segment are given. Find the
coordinates of the midpoint of each segment. (Lesson 9-6)
47. A(3, 4), C(0, 5) 48. M(2, 1), N(6, 9) 49. R(3, 0), S(3, 8)
ALGEBRA Solve each inequality. (Lesson 7-5)
a
50. 5m 5 51. 3 2
52. 4x 16
Lesson 9-8 Sine, Cosine, and Tangent Ratios 481