Download Perimeter, Circumference, and Area

1-8
PART 2
Perimeter, Circumference,
and Area
Vocabulary
Review
Write T for true or F for false.
1. Circumference is the distance around a circle.
2. The distance around a field is its perimeter.
3. Perimeter is measured in square units.
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4. Write perimeter or circumference to describe each measurement below.
Vocabulary Builder
consecutive (adjective) kun SEK yoo tiv
Related Word: sequence
Definition: Consecutive means following in order without interruption.
Example: The numbers 2, 4, 6, 8, . . . are consecutive even numbers.
Non-Example: The numbers 1, 3, 2, 5, 4, . . . are NOT consecutive numbers.
Use Your Vocabulary
Draw a line from each sequence of letters in Column A to the next consecutive
letter in Column B.
Column A
Column B
5. L, M, N, O, . . .
R
6. V, U, T, S, . . .
I
7. A, C, E, G, . . .
P
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Lesson 1-8, Part 2
Key Concept Area
Square
Triangle
Rectangle
Circle
s2
A 5 12bh
A 5 bh
A 5 pr2
A5
8. Circle possible perimeter measurements. Underline possible area measurements.
81 ft2
4p cm
29 mm
27 yd2
Problem 4 Finding Area of a Rectangle
Got It? You are designing a poster that will be 3 yd wide and 8 ft high. How much
paper do you need to make the poster? Give your answer in square feet.
Underline the correct word to complete each sentence.
9. Find the area / perimeter of the poster.
10. The number of yards is greater than / less than the equivalent number of feet.
11. You need your answer in square feet, so convert the width of the poster from
yards to feet.
1 yd 5 3 ft, so 3 yd 5
?
5
ft
13. You need
square feet of paper.
Problem 5 Finding Area of a Circle
Got It? The diameter of a circle is 14 ft. What is the area of the circle in terms of π?
14. Label the diameter and radius of the circle at the right.
15. Use the formula A 5 pr 2 to find the area of the circle in terms of p.
16. The area of the circle is
p ft 2 .
Postulate 1–10 Area Addition Postulate
17. The area of a region is the sum / difference of the areas of its nonoverlapping parts.
Chapter 1
66
ft
ft
Copyright © by Pearson Education, Inc. or its affiliates. All Rights Reserved.
12. Find the amount of paper you need to make the poster.
Problem 6 Finding Area of an Irregular Shape
Got It? Reasoning The figure below shows one way to separate the figure at the
left. What is another way to separate the figure?
3 cm
A1
3 cm
3 cm
A2
9 cm
3 cm
6 cm
A3
3 cm
9 cm
18. Draw segments to show two different ways to separate the figure. Separate the
left-hand figure into three squares.
3 cm
3 cm
9 cm
9 cm
Lesson Check • Do you UNDERSTAND?
Copyright © by Pearson Education, Inc. or its affiliates. All Rights Reserved.
Writing Describe a real-world situation in which you would need to find an area.
19. Suppose you want to paint your room. Explain why you need to find an area.
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Math Success
Check off the vocabulary words that you understand.
perimeter
area
Rate how well you can find the area of irregular shapes.
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review
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get it!
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Lesson 1-8, Part 2