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

The area decreases more rapidly than the lengths of the sides decrease
The area decreases, but less rapidly than the lengths of the sides decrease
The area increases, but rapidly than the lengths of the sides increase
The area increases more rapidly than the lengths of the sides increase

1 answer

When a shape, such as a pentagon, is dilated by a scale factor \( k \), the lengths of the sides are multiplied by \( k \). However, the area of the shape is affected by the square of the scale factor. Specifically, if a shape is dilated by a scale factor \( k \), the area \( A \) of the shape transforms according to the equation:

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

Where \( A' \) is the new area after dilation, and \( A \) is the original area.

If the scale factor \( k \) is less than 1, the following occurs:

  1. The lengths of the sides shrink, as they are multiplied by a fraction (less than 1).
  2. The area shrinks even more, as it is multiplied by \( k^2 \) (which is less than \( k \) when \( k < 1 \)).

Since \( k^2 < k \) for \( k < 1 \), this means that the area decreases more rapidly than the lengths of the sides decrease.

Therefore, the correct answer is:

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