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If the angles of elevations of the top of a tower from two points at distances a and b from the base and in the same straight line with it are complementary then the height of the tower is

Solution

✅ Correct Option: 2

Let the height be hh and the angles be θ\theta and 90−θ90-\theta.

From the first point, tan⁡θ=h/a\tan\theta = h/a. From the second, tan⁡(90−θ)=cot⁡θ=h/b\tan(90-\theta) = \cot\theta = h/b.

Multiplying, tan⁡θ⋅cot⁡θ=1=h2/(ab)\tan\theta \cdot \cot\theta = 1 = h^2/(ab), so h2=abh^2 = ab and h=abh = \sqrt{ab}.

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