Ans: A
Add a point $G$ such that $AG\perp GF$. Note that
Add a point $G$ such that $AG\perp GF$. Note that
$\begin{array}{rcl}
AG & = & BC + DE \\
& = & 4\mbox{ cm}
\end{array}$
and also,
$\begin{array}{rcl}
GF & = & AB + CD + EF \\
& = & 6\mbox{ cm}
\end{array}$
Hence, we have
$\begin{array}{rcl}
AF & = & \sqrt{4^2+6^2} \\
& = & 7.211~102~551\mbox{ cm}
\end{array}$
