Scale Drawing

7-2 Scale Drawings
Important Terms:
Scale Drawing
Scale Factor
Scale Drawing:
a drawing that is similar to the object it represents.
Ex: Map
Scale factor or Scale
A ratio that compares the relation of the scale
model to the actual dimension
I. Identify the scale factor, which is the ratio of,
1.) Every few year, the Grand Place in Brussels, Belgium, is decorated with a large
floral carpet. Suppose the floral carpet is to be 40 meters wide. a designer creates
a scale drawing of the carpet that is 20 cm wide. Find the drawing's scale.
Find the scale factor of the following pairs of items.
Length Item
6 in.120 in.
10 in.60 in.
6 in.84 in. Grizzly Bear
Scale Factor
II. Solve the following scale drawing problems using proportions. Calculator permitted,
but show all steps.
Proportion setup:
1.) On a scale drawing the height of a tree is 6.5 in. Find the actual height of the
tree, if the scale of the model is 1 in to 20 in.
2.) On a map of Pennsylvania, the distance between Philadelphia and
Pittsburgh is 12 in. What is the actual distance if the map scale
is 2 in. = 50 miles?
3.) Mary is driving from Philadelphia to Miami for vacation. If the
actual distance between the cities is 1,200 miles, and the map
scale is 1 in. = 60 miles, what is the map distance between the cities?
Demonstrate Understanding
1.) Find the scale factor if an airplane measures 25.5 feet and the model measures
1.5 feet.
2.) Mr. Patek took a trip to Seattle and bought a miniature version of the Space Needle. If the
Space Needle is 600 ft. tall and the scale factor is 1 in : 75 ft., how tall was the model?
3.) On a road map, the distance between 2 cities is 2.5 inches. The map scale is 1
inch = 30 miles. What is the actual distance between the cities?