1. Lesson 7 – 7 Scale Drawings and Models
Geometry
Lesson 7 – 7
Scale Drawings and Models
Objective:
Interpret scale models.
Use scale factor to solve problems.

2. Scale Model or Scale Drawing
The scale of a model or drawing is the ratio of a length on the model or drawing to the actual length of the object being modeled or drawn.

3. The distance from Nashville to
The scale on the map shown is inch : 40 miles. Find the actual distance from Nashville to Memphis.
Use a ruler to measure
The distance from Nashville to
Memphis is 150 miles.
0.4x = 60
x = 150

4. Find the distance from Nashville to Chattanooga.
87.5 miles

5. What is the scale of the model?
This is a miniature replica of a 1923 Checker Cab. The length of the model is 6.5 inches. The actual length of the car was 13 feet.
What is the scale of the model?
How many times as long as the actual car is the model?
Scale is 1 in : 2 ft
Get the ratio into the same units
The scale model is 1/24 as long as the actual car.

6. Suppose you want to build a model of the St
Suppose you want to build a model of the St. Louis Arch that is no more than 11 inches tall. Choose an appropriate scale and use it to determine the height of the model. Use the information at the left. The actual model is 630 feet.
An approximate model could be 1 in: 60 ft.
630 = 60x
10.5 = x
So the height of the model would be 10.5 inches.

7. Sonya is making a scale drawing of her room on an 8
Sonya is making a scale drawing of her room on an 8.5-by-11-inch sheet of paper. If her room is 14 feet by 12 feet, find an appropriate scale for the drawing and determine the dimensions of the drawing.
Approximately 1.6 feet per in
14 feet / 8.5 inches =
An appropriate model would be 1 in: 1.5 ft.
The dimensions of the
drawing would be :
12 = 1.5x
14 = 1.5x
8 = x
x is appx.9.3

8. Homework
Pg – 4 all, 6 – 16 E, – 48 E