<PRE><B>Question 388066</B>
the angles of elevation to an airplane from two points A and B on level ground are 51 degrees and 68 degrees respectively. The points A and B are 2.5 miles apart, and the airplane is east of both points in the same vertical plane. Find the altitude of the plane.
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The interior angle at point B is 180 - 68 = 112º
Angle C (at the plane) = 180 - (A+B) = 17º
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Use the Law of Sines to find side AC
AB/sin(17) = AC/sin(112)
AC = AB*sin(112)/sin(17) =~ 7.928 miles
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Altitude = AC*sin(51) =~ 6.163 miles
= 32532 feet

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