A garage floor measures 150 feet by 120 feet. A scale drawing of the floor on grid paper uses a scale of 1 unit 15 feet. What are the dimensions of the drawing?

1 Answer
Apr 30, 2017

Answer:

10 feet by 8 feet

Explanation:

I choose the following:

Actual width #->W_a=150ft#
Scaled width #->W_s#

Actual length #->L_a =120ft#
Scaled length #->L_s#

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#color(blue)("Consider width - first principles")#

Using ratio in fraction format gives:

#("Actual")/("Scaled") ->15/1-=W_a/W_s=150/W_s#

Turn up the other way (should have done that at the beginning!)

#("Scaled")/("Actual")->1/15-=W_s/150#

#color(green)(1/15color(red)(xx1)-=W_s/150#

#color(green)(1/15color(red)(xx10/10)=W_s/150#

#10/150=W_s/150#

#W_s->" scale width "=10 feet#
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#color(blue)("Consider length")#

#color(brown)("Using short cut method")#

#L_s/L_a->1/15-=L_s/120#

Multiply both sides by 120

#L_s=8 feet#