Question 12
Refer to the diagram below, in trapezium $ABCD$, $AD\parallel BC$. The line passing through $B$ and parallel to $CD$ intersects the line passing through $C$ and parallel to $AB$ at point $E$. Point $F$ lies inside $ABCD$ such that $\angle FAD=\angle ABC$ and $\angle FDA=\angle DCB$. Given that the area of $ABEF$ is 20 cm² and the area of $DCEF$ is 16 cm², what is the area of $ABCD$?
