Question

In the diagram below, the height of a flagpole is labeled
h
.

A right triangle is formed by a flagpole, the ground, and a line connecting the top of the flagpole to a point on the ground. The leg of the triangle corresponding to the ground is 25 feet long, and the angle formed by the ground and the line going to the top of the flagpole measures 35 degrees. The height of the flagpole is labeled h. A table shows the approximate value of trig ratios: sine of 35 degrees is 0.57, cosine of 35 degrees is 0.82, and tangent of 35 degrees is 0.70.

What is the height of the flagpole?

A.
14.3 ft

B.
17.5 ft

C.
20.5 ft

D.
35.7 ft

Answer 1

The angle given is between the ground (adjacent) and the line to the top (hypotenuse), so tan(35°) = opposite/adjacent = h/25. Thus h = 25·tan(35°) ≈ 25·0.70 = 17.5 ft.

Answer: B.