Question

The area of a trapezium is 360 cm² and its height is 18 cm. If one of the parallel sides is longer than the other by 6 cm, then the two parallel sides are.

Answer 1

The two parallel sides a and b are 17 cm and 23 cm respectively

Explanation:

Area of a trapezium = {(a+b)/2} h

Where

h = height = 18 cm

a = parallel side 1 = x

b = parallel side 2 = x + 6

Area of a trapezium = {(a+b)/2} h

360 = {(x + x + 6) / 2} 18

360 = { (2x + 6) / 2} 18

360 = (2x + 6) 9

360 = 18x + 54

Subtract 54 from both sides

360 - 54 = 18x

306 = 18x

Divide both sides by 18

x = 306 / 18

= 17

x = 17 cm

a = parallel side 1 = x

x = 17 cm

b = parallel side 2 = x + 6

x + 6

= 17 + 6

= 23 cm