Question

A boat is heading towards a lighthouse, whose beacon-light is 141 feet above the water. From point A, the boat's crew measures the angle of elevation to the beacon, 6°, before they draw closer. They measure the angle of elevation a second time from point B at some later time to be 12°. Find the distance from point A to point B. Round your answer to the nearest foot if necessary

Answer 1

678 ft

Explanation:

tan 12° = 141/BC

BC = 141/tan 12° = 663.35 ft

tan 6° = 141/AC

AC = 141/tan 6° = 1341.525 ft

1341.525 ft - 663.35 ft = 678 ft