Find the area of the trapezium ABCD in which AB//DC, AB =18 cm, ∠B=∠C=90∘,CD=12 cm and AD =10 cm.
In trapezium ABCD,
AB||DC, AB=18 cm
∠B=∠C=90∘, CD =12 cm and AD =10 cm
Area of trapezium ABCD
Draw DL⊥AB
∴AL=18−12=6cm
AL =BC
AL=√AD2−AL2
=√102−62=√100−36
=√64=8cm
Now area of trapezium =12(AB+CD)×AL
=12(18+12)×8cm2
=12×30×8=120cm2