A telephone tower casts a 50-foot shadow that makes a 48° angle with the ground. If Fiona wants to find the length of the cable that secures the tower to the ground, how should she set up the problem? Option #1: cos48°=x50 Option #2: cos48°=50x Option #3: cos50°=50x (1 point) Option # is the correct setup.

1 answer

To find the length of the cable that secures the tower to the ground, we can consider the right triangle formed by the tower, the ground, and the cable.

  1. The tower represents the opposite side of the triangle.
  2. The shadow (50 feet) represents the adjacent side of the triangle.
  3. The cable, which is the hypotenuse of the triangle, connects the top of the tower to the ground where the tower is anchored.

Given that the angle is 48°, we can use the cosine function, which relates the adjacent side and the hypotenuse:

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

In this case, the adjacent side is 50 feet (the shadow), and we can label the length of the cable as \( x \).

Thus, the correct equation should be:

\[ \cos(48°) = \frac{50}{x} \]

To solve for \( x \), you can rearrange this:

\[ x = \frac{50}{\cos(48°)} \]

Now let's look at the options given:

  • Option #1: cos48° = x/50
  • Option #2: cos48° = 50/x
  • Option #3: cos50° = 50/x

Option #2 is the correct setup:

\[ \cos(48°) = \frac{50}{x} \]

This means the answer is Option #2.