A vertical tower Stands on a horizontal plane and is surmounted by a vertical flag staff of height h. At a point on the plane, the angles of Elevation of the bottom and the top of the flag staff are `alpha and beta` respectively Prove that the height of the tower is `(htanalpha)/(tanbeta - tanalpha)`

Explanation

Let height be y `DeltaOAC`


`tantheta=BP​`

`tanbeta=(CA)/(OA)`
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`tanbeta=(y+h)/x`

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Let `OA=x`

`x=[y+h​]/tanbeta`

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