trig
posted by tim .
The captain of a ship at sea sights a lighthouse which is 280 feet tall.
The captain measures the the angle of elevation to the top of the lighthouse to be 25.
How far is the ship from the base of the lighthouse?

25=howfar*tan25
Now, I am wondering how he measured the angle of elevation at night....if you have ever been at sea at night, you know the problem: the surface and sky are both black, and you cannot see the horizon.