LESSON Practice A 5-8 Scale Drawings and Scale Models

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Name

LESSON

Date

Class

Practice A

5-8 Scale Drawings and Scale Models

1. A drawing is 10 in. and the actual measurement is 20 ft. What is

the scale?

1 in.
2 ft

2. A model of a planned baseball stadium is 2 ft wide. The actual

stadium will be 200 yd wide. What is the scale?

1 ft
100

1

The scale of a drawing is
4
in.
6 ft. Find the actual

measurement.

3. 4 in.

4. 3 in.

96 ft

5. 1 in.

72 ft

6. 2.75 in.

24 ft

66 ft

The scale is 1 cm
25 m. Find the length each measurement

would be on a scale drawing.

7. 50 m

2 cm

8. 225 m

9. 375 m

9 cm

10. 150 m

15 cm

11. A square has a perimeter of 60 ft. A scale drawing of the figure

1

is made with a scale of
3
in.
5 ft. What is the perimeter of the

scale drawing of the figure?

12. A scale drawing has a scale of 1 in.
10 ft. How long is a line

on the drawing that represents an actual length of 22.5 ft?

13. On a map the distance between Charleston and Mt. Pleasant

is 3.2 cm. The scale is 1 cm
25 mi. What is the actual distance

between these two towns?

6 cm

4 in.

2.25 in.

80 mi

14. A scale model of a house is 1 ft long. The actual house is 36 ft

long. In the model, the door is 2 in. high. How many feet high is

the actual door?

6 ft

15. A scale model of a car is drawn with a scale of 1:12. If the scale

model is 185 mm long, how long is the actual car?

2220 mm

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62

Holt Mathematics

Reading Strategies

5-7 Use Graphic Aids

Problem Solving

5-7 Indirect Measurement

LESSON

LESSON

Write the correct answer.

1. Celine wants to know the width of the

pond. She drew the diagram shown

below and labeled it with the

measurements she made. How wide

is the pond?

Sometimes it is difficult to measure lengths or distances directly.

2. Vince wants to know the distance

across the canyon. He drew the

diagram and labeled it with the

measurements he made. What is the

distance across the canyon?

225 m

85 ft

Danny is 5 feet tall. He casts a shadow that is 12 feet long. At the

same time, a cactus casts a shadow that is 36 feet long. How tall is

the cactus?

The diagram shows the relationship between Danny¡¯s height and

shadow and the height and shadow of the cactus at the same time.

Notice that you can create two triangles from the relationships.

Because the shadows occur in the same place at the same time of

day, the triangles are similar.

?

?

25 ft

54 m

You can use similar triangles to measure lengths and distances

indirectly.

5 ft

12 m

17 ft

50 m

5 ftt

3. Paula places a mirror between

herself and a flagpole. She stands so

she can see the top of the flagpole in

the mirror, creating similar triangles

ABC and EDC. Her eye height is 5

feet and she is standing 6 feet from

the mirror. If the mirror is 25 feet from

the flagpole, how tall is the flagpole?

Round to the nearest foot.

36 ft

12 ft

f

B

12 ft

36 fft

Answer the following questions about the problem and

diagram above.

1. What does the variable h represent in the diagram?

The unknown height of the cactus.

A

C

E

2. Explain why you can write this proportion relating the heights

and shadows.

21 ft

Danny¡¯s height

cactus height

   

Danny¡¯s shadow

cactus shadow

Choose the letter for the best answer.

5. Kim is 56 inches tall. His friend is

42 inches tall. Kim¡¯s shadow is 24

inches long. How long is his friend¡¯s

shadow at the same time?

F 18 in.



G 32 in.

H 38 in.

J 98 in.

4. A shrub is 1.5 meters tall and casts a

shadow 3.5 meters long. At the same

time, a radio tower casts a shadow

98 meters long. How tall is the radio

tower?

A 33 m

B 42 m



C 147 m

D 329 m

Because the triangles are similar and corresponding parts are proportional.

3. Explain how to use the diagram to write the proportion using

numbers and a variable.

Substitute 5 for Danny¡¯s height, 12 for his shadow, h for the cactus

height, and 36 for the length of the cactus shadow.

4. Write the proportion using the numbers and a variable. Then

solve.

5



12

h

 36 ; h = 15

5. How tall is the cactus?

15 ft

59

Copyright ? by Holt, Rinehart and Winston.

All rights reserved.

Holt Mathematics

60

Copyright ? by Holt, Rinehart and Winston.

All rights reserved.

Holt Mathematics

Practice A

5-8 Scale Drawings and Scale Models

Puzzles, Twisters & Teasers

5-7 Puzzling Measurement Puzzle

LESSON

LESSON

1. A drawing is 10 in. and the actual measurement is 20 ft. What is

the scale?

Solve the crossword puzzle.

1 in.  2 ft

Across

2. Corresponding sides of similar figures are ___.

2. A model of a planned baseball stadium is 2 ft wide. The actual

stadium will be 200 yd wide. What is the scale?

5. Use ___ figures and proportions to find an indirect measure.

1 ft  100 yd

6. Use ___ products to solve a proportion.

1

The scale of a drawing is 4 in.  6 ft. Find the actual

measurement.

7. Corresponding ___ of similar figures are congruent.

Down

3. 4 in.

4. 3 in.

5. 1 in.

6. 2.75 in.

1. ___ are similar figures used in indirect measurement.

96 ft

3. A ___ states that two ratios are equivalent.

7. 50 m

2

P

T

R

O

3

P

O

R

T

4

2 cm

I

O

I

R

N

A

O

D

N

P

G

O

L

R

E

T

S

5

S

I

M

N

I

A

L

L

A

I

A

N

9. 375 m

9 cm

10. 150 m

15 cm

13. On a map the distance between Charleston and Mt. Pleasant

is 3.2 cm. The scale is 1 cm  25 mi. What is the actual distance

between these two towns?

R

O

S

6 cm

4 in.

2.25 in.

80 mi

14. A scale model of a house is 1 ft long. The actual house is 36 ft

long. In the model, the door is 2 in. high. How many feet high is

the actual door?

S

T

6 ft

O

7

8. 225 m

12. A scale drawing has a scale of 1 in.  10 ft. How long is a line

on the drawing that represents an actual length of 22.5 ft?

R

E

C

66 ft

11. A square has a perimeter of 60 ft. A scale drawing of the figure

1

is made with a scale of 3 in.  5 ft. What is the perimeter of the

scale drawing of the figure?

R

6

24 ft

The scale is 1 cm  25 m. Find the length each measurement

would be on a scale drawing.

4. ___ measurement can be used to find distances that cannot be

measured directly.

1

72 ft

G

L

E

15. A scale model of a car is drawn with a scale of 1:12. If the scale

model is 185 mm long, how long is the actual car?

S

2220 mm

Copyright ? by Holt, Rinehart and Winston.

All rights reserved.

61

Copyright ? by Holt, Rinehart and Winston.

All rights reserved.

Holt Mathematics

Copyright ? by Holt, Rinehart and Winston.

All rights reserved.

84

62

Holt Mathematics

Holt Mathematics

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