SOLUTION: From the top of a lighthouse 139 ft above the surface of the water, the angle of depression of a boat is observed to be 29.4 degrees . Find the horizontal distance from the boat to

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Question 906370: From the top of a lighthouse 139 ft above the surface of the water, the angle of depression of a boat is observed to be 29.4 degrees . Find the horizontal distance from the boat to the lighthouse.
Work to three significant digits.
Answer by MathLover1(20849) About Me  (Show Source):
You can put this solution on YOUR website!
We have C=90-29.4=60.6degrees and BC=139ft
so,in ABC we have
AB%2FBC=tan%28C%29
than,
AB=BC%2Atan%28C%29=139%2A+tan%2860.6%29=139%2A1.28568=178.71ft