Scale Drawings
Common Core Standard: Solve problems involving scale drawings of geometric figures, including computing actual lengths
and areas from a scale drawing and reproducing a scale drawing at a different scale.

Scale – is the ratio of the length in a drawing or model to the length of the real object or figure

In the real world scale is used daily
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Scale factor- is the ratio used to determine how the scale and actual model are related

Example: Jalen made a treasure hunt map. The treasure is 38 cm away from his location. If each 1 cm on the scale
drawing equals 7 meters, then how far he is from treasure?
o
There are multiple approaches to this question, one of which is shown below. Know that any method is
correct as long as it results in the correct answer and can be explained
o
Proportion method, create two equal ratios, for this instance the scale forms one ratio and the actual
length forms the other ratio

1 𝑐𝑚
7𝑚
=
38 𝑐𝑚
,
𝑥
using these proportions, we know that 1cm = 38 cm, this means that the ratios are
related by multiplying by 38


7 ● 38 = 266 m, so the treasure is 266 meters from his location
Example: The picture below is a scale drawing of several monuments. In this drawing, the Eiffel Tower is about 4.5
units in measurement. In real life the Eiffel Tower measures 350 yards tall. Determine the scale factor.
o
Again, there are numerous methods to determine solutions. Below is one of these methods:
o
A scale factor is usually has a one for one of the numbers, so to get to one using the information above,
divide 4.5 by 4.5
o
This also means that 350 must be divided by 4.5
o
350 ÷ 4.5 = 77 9
o
So the scale factor is 1 unit to 77 9 yards
7
7