Question

In Sichuan, China, Bernards stands at the top of the Jinping-1 dam and measures the angle of depression down to where Benjamin is standing at 1999 feet from the base of the dam. If the angle of depression is 26.6 degrees, how tall is the dam? Round to the nearest foot.​

Answer 1

This illustrates a right triangle.

Given:

a(height) = 2457 ft.

∠A = 22°23' ; which is the elevation and reflects the a(height)

Find:

b(base)

Solution:

Using the law of cosine, specifically tan∠ = opposite side÷adjacent side

By analysis, tan∠A = a÷b

Since we are finding b, the formula will be derived into:

b = a÷tan∠A

Find b(base):

b = 2457 ft. ÷ tan22°23' ; substituting the numbers

b ≈ 5,966.05 ft. ; Final Answer

Explanation: