Answer:
The scale factor is 20.
Step-by-step explanation:
The scale factor is the ratio of the corresponding side lengths (or areas or volumes) of the two similar figures. In this case, we are given the areas of the front sides of the toy building and the real building, and we want to find the scale factor between them.
Let x be the scale factor. Then, the area of the front side of the real building is x^2 times the area of the front side of the toy building. We can set up the equation:
x^2 * 1 square foot = 400 square feet
Solving for x, we get:
x^2 = 400
x = sqrt(400)
x = 20
Therefore, the scale factor between the toy building and the real building is 20.