The angle of elevation of the top of a tower standing on a horizontal plane from a point C is α. After walking a distance d towards the foot of the tower the angle of elevation is found to be β. The height of the tower is

Question

Philoid · Accepted Answer

Let h be the height of the tower on horizontal plane.

Let α be the angle of elevation from point C and β be the angle of elevation from point B

Given CB = d

In Δ PCB

tan a (α) =

x =

In Δ CDB

tan b(β) =

tan b =

tan b () =

h tan b - d tan a tan b = h tan a

h (tan b – tan a) = d tan a tan b

h =