An observer $1.6$ metres tall is $10.5$ metres away from a tower $22$ metres high.Determine the angle of elevation of the top of the tower from the eye of the observer.
Given: An observer $1.6$ metres tall is $10.5$ metres away from a tower $22$ metres high.
To do: To find the angle of elevation of the top of the tower from the eye of the observer.
Solution:
Let $\theta$ be the angle of elevation of the top of the tower from the eye of the observer.
As given, the height of the observer is $CD=1.5\ m$
Height of the tower $AB=22\ m$
$AE=AB-BE=22-1.5=20.5$ [$\because BE=CD=1.5\ m$]
In $\vartriangle AEC$,
$tan\theta=\frac{AE}{CE}$
$tan\theta=\frac{20.5}{20.5}$ [$\because CE=BD=20.5$]
$tan\theta=1=tan45^o$
$\Rightarrow \theta=45^o$
Thus, the angle of elevation of the top of the tower from the eye of the observer is $45^o$.
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