Answer:
786.9 feet to the nearest tenth.
Step-by-step explanation:
In the triangle formed between the boat, base of the lighthouse and the top of the lighthouse, the opposite side to angle 21 49' is the height of the lighthouse and the distance (d) of the boat is the adjacent side.
So we have:
tan 21 49 = 315 / d
d = 315/ tan21 49
= 786.89 ft.
