To find the distance \( x \) between the foot of the ladder and the base of the building using cosine, we can use the following cosine formula in a right triangle:
\[ \cos(\theta) = \frac{\text{adjacent side}}{\text{hypotenuse}} \]
In this case, the angle \( \theta \) is 55°, the adjacent side is the distance \( x \) we want to find, and the hypotenuse is the length of the ladder (16 feet).
So we can write:
\[ \cos(55°) = \frac{x}{16} \]
Now, solving for \( x \):
\[ x = 16 \cdot \cos(55°) \]
Next, we can calculate \( \cos(55°) \):
\[ \cos(55°) \approx 0.5736 \]
Now, substitute this value into the equation:
\[ x \approx 16 \cdot 0.5736 \approx 9.1776 \]
Rounding to the nearest hundredth:
\[ x \approx 9.18 , \text{ft} \]
Thus, the correct response is \( x = 9.18 , \text{ft} \).