The parallel sides of a trapezium are 12 cm and 9 cm and the distance between them is 8 cm.

Area of the trapezium $=\frac{1}{2} \times$ (sum of the parallel sides) $\times$ distance between the parallel sides

$=\frac{1}{2} \times(12+9) \times 8$

$=21 \times 4$

$=84 \mathrm{~cm}^{2}$

So, the area of the trapezium is 84 cm2.