Question 730613
.
From the top of a 210-ft lighthouse, the angle of depression to a ship in the 
ocean is 15 degrees. How far is the ship from the base of the lighthouse?
A. 874ft
B. 478ft
C. 784ft
D. 748ft
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<pre>
An equation to use is

    h = d*tan(a),


where h is the height of the lighthouse and d is the distance from the ship to the base of the lighthouse.


We assume that the Earth is flat (and the water surface in the ocean is flat, too) and that
the base of the lighthouse is at the level of water surface.


So, our equation is

    210 = d*tan(15°),

    d = {{{210/tan(15^o)}}} = {{{210/0.26794919243)}}} = 783.73 feet.


<U>ANSWER</U>.  The closest answer in the list is option (C).
</pre>

Solved.


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The answer in the post by @lynnlo is incorrect.

Simply ignore it.