Question 20
In the figure below, $ABC$ is a triangle with $AB=10$ cm and $BC=40$ cm. Points $D,E$ lie on side $AC$ and point $F$ on side $BC$ such that $EF\parallel AB$ and $DF\parallel EB$. Given that $BE$ is an angle bisector of $\angle ABC$ and $AD=13.5$ cm, find $CD$ in cm.
