Problema Solution
the angle of depression from the top of a tower of a point A on the ground is 30degree. on moving a distance of 20m from the point A towards the foot of the tower to a point B, the angle of elevation of the top of the tower from the point B is 60 degree. find the height of the tower and its distance from th point A
Answer provided by our tutors
Let CD be the tower.
Suppose BC = x m and CD = h m.
Given, ∠ADE = 30° and ∠CBD = 60°.
∠DAC = ∠ADE = 30° (Alternate angles)
In ΔACD,
In ΔBCD,
From (1) and (2), we have
∴ 20 + x = 3x
⇒ 2x = 20
⇒ x = 10
∴ Height of the tower =
Distance of tower from A = AC = (20 + x) m = (20 + 10) m = 30 m