Given data:
The length of the wire is l= 50 foot.
The given base length is b= 35 feet.
The expression for the height of the antena is,
[tex]\begin{gathered} l^2=b^2+h^2 \\ h^2=l^2-b^2 \\ h=\sqrt[]{l^2-b^2} \end{gathered}[/tex]Substitute the given values in the above expression.
[tex]\begin{gathered} h=\sqrt[]{(50ft)^2-(35ft)^2} \\ =\sqrt[]{1275}\text{ ft} \\ =35.707\text{ ft} \\ \approx36\text{ ft} \end{gathered}[/tex]Thus, the height of the antena is 36 ft.