Question

From the top of a lighthouse 210 feet high, the angle of depression of a boat is 7°. Find the distance from the boat to the foot of the lighthouse. The lighthouse was built atsea level. round measure of distance to the nearest hundredth.

Answer 1

Apply the trigonometric function:

Tan a = opposite side / adjacent side

Where:

a = angle = 7°

opposite side = 210

adjacent side = x

Replacing:

Tan 7 = 210/x

x =210/tan 7

x= 1,710.31 feet

The distance from the boat to the foot of the lighthouse is 1,710.31 feet