From the top of a tower h m high, angle of depression of two objects, which are in line with the foot of the tower are α and β (β >α). Find the distance between the two objects.

Given: the height of tower is h m.

ABD = α & ACD = β


Let CD = y and BC = x



In ∆ABD,







In ∆ACD,





Comparing eq. 1 and eq. 2,





x = h (cot α – cot β)


Hence, we have got the required distance between the two points, i.e. h (cot α – cot β)


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