Q7 of 107 Page 12

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


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 =


tan b () =


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


h (tan b – tan a) = d tan a tan b


h =


h =


h =

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