The area of a trapezium is 140 cm$$^2$$​and the perpendicular distance between its parallel sides is 7 cm. If the length of one of the parallel sides is 28 cm, what is the length of the other parallel side?

Correct option is A

Given:

- Area of trapezium = 140 cm²

- Distance (height) between parallel sides = 7 cm

- One parallel side (a) = 28 cm

- Other parallel side = b (unknown)

Formula Used:

Area of trapezium = $$(\frac{1}{2}) × (a + b) × h$$​​

Solution:

​$$140 = (\frac{1}{2}) × (28 + b) × 7$$​​

280 = (28 + b) × 7

40 = 28 + b

b = 40 - 28 = 12 cm

The length of the other parallel side is 12 cm.