A dilated figure has a surface area of 10,990.8 in.^2 . The figure was dilated by a scale factor of 6. What is the surface area of the original figure?

A. 305.3 in.^2
B. 395,668.8 in.^2
C. 1,831.8 in.^2
D. 915.9 in.^2

1 answer

To find the surface area of the original figure before dilation, we need to use the relationship between the surface area of a dilated figure and the scale factor. When a figure is dilated by a scale factor of \( k \), the surface area of the dilated figure is multiplied by \( k^2 \).

In this case, the scale factor \( k = 6 \). Therefore, the surface area of the dilated figure (10,990.8 in²) can be expressed in terms of the original surface area \( A \) as follows:

\[ \text{Surface Area of Dilated Figure} = k^2 \times \text{Surface Area of Original Figure} \]

Substituting in the known values:

\[ 10,990.8 = 6^2 \times A \]

Calculating \( 6^2 \):

\[ 6^2 = 36 \]

Now substituting this back in:

\[ 10,990.8 = 36 \times A \]

To find \( A \), divide both sides by 36:

\[ A = \frac{10,990.8}{36} \]

Calculating \( A \):

\[ A = 305.3 \text{ in}^2 \]

Thus, the surface area of the original figure is:

\(\boxed{305.3 \text{ in}^2}\) (Option A)