A person is standing exactly [tex]36 \, \text{ft}[/tex] from a telephone pole. There is a [tex]30^{\circ}[/tex] angle of elevation from the ground to the top of the pole.

What is the height of the pole?

A. [tex]12 \, \text{ft}[/tex]

B. [tex]12 \sqrt{3} \, \text{ft}[/tex]

C. [tex]18 \, \text{ft}[/tex]

D. [tex]18 \sqrt{2} \, \text{ft}[/tex]



Answer :

To determine the height of the telephone pole, we can use trigonometry. Specifically, we'll use the tangent function, which relates the angle of elevation ([tex]\(\theta\)[/tex]), the distance from the observation point to the base of the pole (d), and the height of the pole (h).

Given:
- The distance from the person to the pole (d) = 36 feet
- The angle of elevation ([tex]\(\theta\)[/tex]) = [tex]\(30^\circ\)[/tex]

We know from trigonometry that:
[tex]\[ \tan(\theta) = \frac{\text{opposite}}{\text{adjacent}} \][/tex]

In this context:
- The "opposite" side is the height of the pole (h).
- The "adjacent" side is the distance from the person to the pole (d).

Thus, we have the equation:
[tex]\[ \tan(30^\circ) = \frac{h}{36} \][/tex]

Now, [tex]\(\tan(30^\circ)\)[/tex] is a known value:
[tex]\[ \tan(30^\circ) = \frac{1}{\sqrt{3}} \][/tex]

Substituting this into our equation gives:
[tex]\[ \frac{1}{\sqrt{3}} = \frac{h}{36} \][/tex]

To solve for [tex]\(h\)[/tex], we multiply both sides by 36:
[tex]\[ h = 36 \times \frac{1}{\sqrt{3}} \][/tex]

To rationalize the denominator:
[tex]\[ h = 36 \times \frac{1}{\sqrt{3}} = 36 \times \frac{\sqrt{3}}{3} = 36 \div 3 \times \sqrt{3} = 12\sqrt{3} \][/tex]

Now, verifying the exact numeric result, the height of the pole is approximately 20.784609690826528 feet.

Therefore, the correct option that matches this height in its simplest form is:
[tex]\[ \boxed{12\sqrt{3}\text{ ft}} \][/tex]