Trigonometrymedium · Past Paper
Angle of elevation of a cloud from a point 60 m above a lake is 30° and depression of its reflection in lake is 60°. Height of cloud?
A120 m
B60 m
C180 m
D90 m
✓ Correct Answer: A — 120 m
Let cloud height be H. (H-60)/d = tan 30, (H+60)/d = tan 60. d = (H-60)√3 = (H+60)/√3. 3H-180 = H+60 => 2H=240, H=120.
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