For this problem we use similar triangles properties. Since the triangles are similar the sides of the triangles are proportional, meaning that
[tex]\begin{gathered} \frac{\text{x}}{7ft}=\frac{65ft}{5ft}=13 \\ \end{gathered}[/tex]
Solving for x we get:
[tex]x=13\cdot7ft=91\text{ ft}[/tex]
Answer: 91 ft.
