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)