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Question
The angle of elevation of the top of a tower at a distance of 120 m from a point A on the ground is 45°. If the angle of elevation of the top of a flagstaff fixed at the top of the tower, at A is 60°, then find the height of the flagstaff. [use √3=1.73]
Solution
Solution:
Let AB is the tower of height h meter and AC is flagstaff of height x meter.
∠APB=45° and ∠BPC =60°
`Tan 60 = (x+h)/120`
`sqrt3=(x+h)/120`
`x=120sqrt3-h`
`tan 45=h/120`
therefore height of the flagstaff =
`=120sqrt3-120`
`=120(sqrt3-1)`
`=120 xx73`
`=87.6 cm`
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