Question 12
In rectangle $ABCD$, point $E$ lies on $AB$. Points $M,N$ lie on $CE$, in the order $C,M,N,E$, with $CM=MN=NE$. Line $DN$ meets side $AB$ at $F$, as shown. The two shaded triangles $DMN$ and $ENF$ have total area $12\text{ cm}^2$. Find the area of rectangle $ABCD$.
