• scale drawing

• scale model

• scale

• Solve problems involving scale drawings.

MAPS Use the map to find the actual distance from Bingston to Alanton.

Use an inch ruler to measure the map distance. The map distance is about 1.5 inches.

Use a Scale Drawing

Method 1 Write and solve a proportion.

Use a Scale Drawing

map

actualactual

map

Find the cross products.

Simplify.

Method 2 Write and solve an equation.

a = 5m

Use a Scale Drawing

Words

Variable

Equation

The actual distance is 5 miles per inch of map distance.

Let a represent the actual distance in miles.Let m represent the map distance in inches.

a = 5 ● m

a = 5(1.5) or 7.5

Write the equation.

Replace m with 1.5 and multiply.

Answer: The actual distance from Bingston to Alanton is 7.5 miles.

A. A

B. B

C. C

D. D A B C D

0% 0%0%0%

A. 7.4 miles

B. 8.5 miles

C. 9.2 miles

D. 9.8 miles

MAPS Use the map to find the actual distance from Springfield to Capital City. The map distance is about 1.4 inches.

SCALE DRAWINGS A wall in a room is 15 feet long. On a scale drawing it is shown as 6 inches. What is the scale of the drawing?

Write a ratio comparing the length of the drawing to the actual length of the room. Using x to represent the actual length of the room, write and solve a proportion to find the scale of the drawing.

Find the Scale

Answer: So, the scale is 1 inch = 2.5 feet.

Find the Scale

Length of room Scale Drawing

scale drawing length scale drawing lengthactual length actual length

Find the crossproducts.

Multiply. Then divide each side by 6.

Simplify.

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

A. 1 inch = 2.1 feet

B. 1 inch = 2.4 feet

C. 1 foot = 2.1 inches

D. 1 foot = 2.4 inches

SCALE DRAWINGS The length of a garage is 24 feet. On a scale drawing the length of the garage is 10 inches. What is the scale of the drawing?

Find the Scale Factor

Find the scale factor for the drawing in Example 2.

Convert 2.5 feet to inches.

The scale factor is or 1:30. This means that the drawing

is the size of the actual room.

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

A. 1 : 22.5

B. 1 : 25.6

C. 1 : 28.8

D. 1 : 30.5

Find the scale factor for the drawing of the garage in the previous Check Your Progress exercise.

STATUE OF LIBERTY Auguste Bartholdi created several smaller models of the Statue of Liberty before creating the 152-foot statue that stands in New York Harbor. One such model was only 21 inches tall. What is the scale of this model to the final version? Use the scale to determine the length of the statue’s index finger on the model, which is 8 feet long on the actual statue.

Construct a Scale Model

Determine the scale of the model to the final version.

The scale of the model to the actual statue is 1 inch 7.2 feet.

Construct a Scale Model

Find the cross products.

Multiply. Then divide each side by 21.

model heightactual height

Simplify.

Use this scale to find the length of the statue’s index finger on the model.

Answer: The finger in the model is about 1.1 inches long.

Construct a Scale Model

1 ● 8 = 7.2 ● x Find the cross products.

Multiply. Then divide each side by 7.2.

model heightactual height

Simplify.

A. A

B. B

C. C

D. D A B C D

0% 0%0%0%

A. about 0.67 inch

B. about 0.75 inch

C. about 0.84 inch

D. about 0.92 inch

STATUE Marnie created a model of her town’s statue of Jebediah Springfield. Her model was 6 inches high. The actual statue is 27 feet tall. What is the scale of this model to the actual statue? Use the scale to determine the length of the statue’s mustache on the model, which is 3 feet long on the actual statue.