Area of trapezium =
12×(Sum of parallel lines)×height
For 2 cm, 4 cm, 3 cm
Area of trapezium
= 12×(2+4)×3 = 9 cm2
For 4 cm, 6 cm, 2 cm
Area of trapezium
= 12×(4+6)×2 = 10 cm2
For 3 cm, 5 cm, 4 cm
Area of trapezium
= 12×(3+5)×4 = 16 cm2
For 5 cm, 7 cm, 3 cm
Area of trapezium
= 12×(5+7)×3 = 18 cm2