One of the similar triangles property is: corresponding sides has the same ratio, then:
[tex]\frac{10}{85}=\frac{6}{x}[/tex]Now solve for x:
[tex]\begin{gathered} x=\frac{6\cdot85}{10} \\ x=\frac{510}{10} \\ x=51 \end{gathered}[/tex]Answer: the flagpole is 51 ft tall.
