Pre-Algebra Chapter 9

62. CRITICAL THINKING Tell whether the product of a rational number like
8 and an irrational number like 0.101001000… is rational or irrational.
Explain your reasoning.
Standardized
Test Practice
Extending
the Lesson
63. WRITING IN MATH Answer the question that was posed at the beginning
of the lesson.
How can squares have lengths that are not rational numbers?
Include the following in your answer:
• an example of a square whose side length is irrational, and
• an example of a square that has a rational side length.
64. Which number can only be classified as a rational number?
A 1 2 B 2 C 2 D 2
65. Which statement is not true?
A All integers are rational numbers.
B Every whole number is a natural number.
C All natural numbers are integers.
D Every real number is either a rational or irrational number.
66. Heron’s formula states that if the measures
of the sides of a triangle are a, b, and c, the
area A s(s )(s a)(s b), c where s is
one-half the perimeter. Find the area of the
triangle at the right. Round to the nearest
tenth, if necessary.
67. Find the area of a triangle whose sides measure
65 feet, 82 feet, and 95 feet.
8 m
12 m
5 m
68. Make a Conjecture Is the area of any triangle always a rational number?
Support your answer with an example.
Maintain Your Skills
Mixed Review
Getting Ready for
the Next Lesson
www.pre-alg.com/self_check_quiz
Estimate each square root to the nearest whole number. (Lesson 9-1)
69. 54 70. 126 71. 8.67
ALGEBRA List three solutions of each inequality. (Lesson 8-10)
72. y x 73. y x 5 74. y x 3
ALGEBRA Solve each inequality. (Lesson 7-6)
75. 3x 2 17 76. 2y 9 3
Express each ratio as a unit rate. Round to the nearest tenth, if necessary.
(Lesson 6-1)
77. $8 for 15 cupcakes 78. 120 miles on 4.3 gallons
BASIC SKILL Use a ruler or straightedge to draw a diagram that shows
how the hands on a clock appear at each time.
79. 3:00 80. 9:15 81. 10:00
82. 2:30 83. 7:45 84. 8:05
Lesson 9-2 The Real Number System 445