Answer:
1420 feet
Explanation:
You want the distance to an island when the angle of elevation to a helicopter 1150 ft above the island is 39°.
Tangent
The tangent ratio is ...
Tan = Opposite/Adjacent
The unknown distance d is adjacent to the 39° angle of elevation to the helicopter, and the height of the helicopter is the opposite side. Using these values, we have ...
tan(39°) = (1150 ft)/d
d = (1150 ft)/tan(39°) ≈ 1420 ft
The distance to the island is 1420 feet.
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Additional comment
The angle of elevation is the same as the angle of depression between the same two points.