KEY
NOTES: Scale Drawings
A scale drawing represents something that is too large or too small to be drawn at actual size.
A map is an example of a scale drawing!
The scale gives the
relationship between the
distance on the map and the
actual distance.
We can use the scale on a map to find out the actual distance between cities and landmarks.
To do this, we need to write and solve a proportion.
Example 1: On a map of Florida, the distance between Coral Springs and Fort Lauderdale is
about 4.1 centimeters. The scale on the map is 1 centimeter = 4.5 kilometers. What is the
actual distance?
=
x=
x = 18.45km
Example 2: On a map of North Carolina, the distance between Raleigh and Charlotte is 3
inches. The scale on the map is 1 inch = 40 miles. What is the actual distance?
=
x=
x = 130 miles
A blueprint is another example of a scale drawing!
Example 3: On the blueprint of the pool, each square has a side length of 0.25 inch. What is
the actual width of the pool?
There are 6 squares along each side of the pool, so the
blueprint’s width is 0.25 6 = 1.5
=
x=
x=
Scale
0.25 in. = 2 ft.
x = 12 ft
Try it! Refer to the blueprint of the garden shown below. Each square has a side length of inch.
1. What is the length of the garden on the blueprint?4 in
2. Find the actual length of the garden. 16 ft
1’’ = 4 feet
3. The butterfly bush and the water fountain are 1 inches
apart. Find the actual distance.
5 ft
Example 4:
Inside the Lincoln Memorial, the chamber that features the marble statue of Abraham Lincoln
has a height of 60 feet. Suppose a scale model of the chamber has a height of 4 inches. What is
the scale of the model?
=
OR 1 inch = 15 feet
Example 5: Scale Factor
a) Suppose a scale model has a scale of 2 inches = 3 feet. What is the scale factor?
b) Suppose the scale is 2 inches = 4 yards. What is the scale factor? 1 yard = 3 feet
a)
b)
=
=
=
=
=
OR 1 : 18, in reality the object is 18 times bigger than the model.
=
OR 1 : 72