The scale drawing of a porch is 8 inches wide by 12 inches long. If the actual porch is 12 feet wide, what is the length of the porch?

The length of the porch is 18ft

Explanation:

When we do a scale drawing, each unit in the scale drawing represents some other unit in the actual thing that is being drawn, defined by a factor of scale k.

In this case, we know that in the scale drawing the porch is 8 inches wide, and we know that the actual width of the porch is 12 ft.

Then for a factor of scale k we have:

8 in = k*12 ft

(8in/12 ft) = k.

And this scale factor is the same for every measure of the drawing.

Then if the length of the actual porch is L, the length in the scale drawing will be k*L

And we know that the length in the scale drawing is 12 inches, then:

12 in = k*L

12 in = (8in/12 ft)*L

12 in*(12ft/8in) = L = 18ft

The length of the porch is 18ft