Question

Trisha made a scale drawing of a house and its lot. The front patio is 9 millimeters wide in the drawing. The actual patio is 18 meters wide. What scale factor does the drawing use?

Simplify your answer and write it as a ratio, using a colon.

Answer 1

To find the scale factor, we can set up a proportion using the width of the drawing and the width of the actual patio:

Drawing width / Actual width = Scale factor

Let's substitute the given values into the proportion:

9 millimeters / 18 meters = Scale factor

As the units do not match, we need to convert one of them. Since 1 meter is equal to 1000 millimeters, we can convert the actual width to millimeters:

18 meters = 18 * 1000 = 18000 millimeters

Now we can calculate the scale factor:

9 millimeters / 18000 millimeters = Scale factor

Simplifying the fraction, we get:

1/2000 = Scale factor

Therefore, the scale factor of the drawing is 1:2000