Determine how dilation affect the area of a pentagon when the sides of the pentagon are dilated by a scale factor less than 1.

a. The area decreases, more rapidly than the lengths of the sides decrease
b. The area increases, more rapidly than the lengths of the sides increase
c. The area increases, but less rapidly than the lengths of the sides increase
d. The area decreases, but less rapidly than the lengths of the sides decrease

1 answer

To determine how dilation affects the area of a pentagon when the sides are dilated by a scale factor less than 1, we need to understand the relationship between linear dimensions (sides) and area.

When a shape is dilated by a scale factor \( k \) (where \( 0 < k < 1 \) in this case), the new area \( A' \) of the shape can be calculated using the formula:

\[ A' = k^2 \cdot A \]

where \( A \) is the original area.

Since \( k \) is less than 1, \( k^2 \) will also be less than 1. This means that the new area \( A' \) will be smaller than the original area \( A \). Specifically, because \( k^2 \) decreases more sharply than \( k \) itself (because squaring a number between 0 and 1 yields a smaller number), the area decreases more rapidly than the lengths of the sides.

Thus, the correct answer is:

a. The area decreases, more rapidly than the lengths of the sides decrease.