The Solution:
Representing the given in a diagram, we have
By similarity theorem, we have that:
[tex]\frac{BA}{BT}=\frac{BC}{BD}[/tex]So,
[tex]\begin{gathered} BA=1.68m \\ BT=h=(1.68+x)m \\ BC=0.21m \\ BD=17.25m \end{gathered}[/tex]Substituting these values in the formula above, we get
[tex]\frac{1.68}{1.68+x}=\frac{0.21}{17.25}[/tex]Solving for x:
We shall cross multiply,
[tex]0.21(1.68+x)=1.68\times17.25[/tex][tex]0.3528+0.21x=28.98[/tex][tex]0.21x=28.98-0.3528=28.6272[/tex]Dividing both sides by o.21, we get
[tex]x=\frac{28.6272}{0.21}=136.32\text{ m}[/tex]The height of the tower is
[tex]h=1.68+x=1.68+136.32=138m[/tex]Therefore, the correct answer is 138 meters.
