COURSE 2 LESSON 5-7
Maps and Scale Drawings
The scale of a drawing is 1 in. : 6 ft. Find the actual
length for a drawing length of 4.5 in.
Write the scale of the drawing, 1 in. = 6 ft, as 1 in. . Then write a proportion in
6 ft
which each ratio compares inches to feet.
Let n represent the actual length.
drawing (in.)
actual (ft)
drawing (in.)
actual (ft)
1
4.5
=
6
n
1n = 6(4.5)
n = 27
Write cross products.
Simplify.
The actual length is 27 ft.
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COURSE 2 LESSON 5-7
Maps and Scale Drawings
On a map of North Carolina, the map distance from Asheville
to Raleigh would be about 4.4 cm. Find the actual distance from
Asheville to Raleigh. The scale on the map is 1cm : 75 km.
map (cm)
actual (km)
map (cm)
actual (km)
1
4.4
=
75
n
1n = 75(4.4)
Write a proportion.
Write cross products.
n = 330
Simplify.
The actual distance from Asheville to Raleigh is about 330 km.
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COURSE 2 LESSON 5-7
Maps and Scale Drawings
The actual length of the wheelbase of a mountain bike is
260 cm. The length of the wheelbase in a scale drawing is 4 cm. Find
the scale of the drawing.
scale length
actual length
4
1
=
260
65
Divide each measure by the GCF, 4.
The scale is 1 cm : 65 cm.
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COURSE 2 LESSON 5-7
Maps and Scale Drawings
1. The scale of a map is 1 cm : 25 km. Find the actual distance for a map
distance of 6.2 cm.
155 km
2. The actual length of a machine part is 40 in. The length of the machine
part in a scale drawing is 5 in. Find the scale of the drawing.
1 in. : 8 in.
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