Here, $$AB=18$$cm, $$BC=10$$cm, $$AF=6$$cm, $$AE=10$$cm and $$BE=8$$cm
Area of shaded portion$$=$$Area of rectangular ABCD$$-$$(Area of $$\Delta$$FAE$$+$$Area of $$\Delta$$EBC)
$$=(AB\times BC)-\left(\dfrac{1}{2}\times AE\times AF+\dfrac{1}{2}\times BE\times BC\right)$$
$$=(18\times 10)-\left(\dfrac{1}{2}\times 10\times 6+\dfrac{1}{2}\times 8\times 10\right)$$
$$=180-(30+40)$$
$$=180-70=110cm^2$$.