Question

A 16-foot ladder leans against a wall so that the ladder’s angle of elevation is 55°. Find x, the distance between the foot of the ladder and the base of the building. Use cosine to solve for the missing side and round your answer to the nearest hundredth.(1 point)
Responses

x=9.18 ft.
x equals 9.18 ft.

x=13.11 ft.
x equals 13.11 ft.

x=27.90 ft.
x equals 27.90 ft.

x=52.87 ft.

1 answer

To find the distance \( x \) between the foot of the ladder and the base of the building, we can use the cosine function.

The cosine of an angle in a right triangle is defined as the ratio of the adjacent side (which is \( x \) in this case) to the hypotenuse (the length of the ladder).

\[ \cos(\theta) = \frac{\text{adjacent}}{\text{hypotenuse}} \]

In this case:

  • \( \theta = 55^\circ \)
  • The hypotenuse (length of the ladder) = 16 feet.

The formula becomes:

\[ \cos(55^\circ) = \frac{x}{16} \]

To find \( x \), we can rearrange the equation:

\[ x = 16 \cdot \cos(55^\circ) \]

Now, we calculate \( \cos(55^\circ) \):

\[ \cos(55^\circ) \approx 0.5736 \]

Now we can find \( x \):

\[ x \approx 16 \cdot 0.5736 \approx 9.1776 \]

Rounding to the nearest hundredth:

\[ x \approx 9.18 \text{ ft} \]

Thus, the correct answer is:

x equals 9.18 ft.