Question 15In square $ABCD$, $E$ and $F$ lie on $AD$ and $CD$ respectively, with $3DE=3FC=AB$. Segments $BF$ and $CE$ meet at $G$. The square has area $140\ \mathrm{cm}^2$. Find the area of quadrilateral $EDFG$. $7\ \mathrm{cm}^2$$14\ \mathrm{cm}^2$$21\ \mathrm{cm}^2$$28\ \mathrm{cm}^2$None of the above
