The area of a trapezium is 40 cm². Its parallel sides are 12 cm and 8 cm. The distance between the parallel sides is

4 cm.

The distance between the parallel sides is height of the trapezium.

Area of a trapezium = \(\frac{\text{Sum of parallel sides}}{2 }\) x height

40 = \(\frac{\text{12 + 8}}{2 }\) x h

40 = \(\frac{\text{20}}{2 }\) x h

40 = 10h

h = 4 cm