7-2 Scale Drawings

Important Terms:

Scale DrawingScale 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,

actual

model

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.

Item 

Tree

Couch

Grizzly Bear

Model Length

6 in.

10 in.

6 in.

Actual Length

120 in.

60 in.

84 in.

Scale Factor

II. Solve the following scale drawing problems using proportions. Calculator permitted, but show all steps.

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.

Proportion setup: =

scale factor

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

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?

1.) Find the scale factor if an airplane measures 25.5 feet and the model measures 1.5 feet.

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?