Example:
The lengths of the parallel sides of a trapezoid are 9 cm and 7cm. Its area is 18 sq cm. Find the distance between the parallel lines.

Solution: The area of a trapezoid is (A ) =1/2 * (a+b) * h.
Given that,
a = 9 cm, b = 7 cm and A = 18 sq cm.
h = 2A/(a+b)
h = (2*18)/(9+7)
h = 36/16
h = 2.25 cm.
\ The distance between the parallel lines = 2.25 cm.

Directions: Read the above example carefully and answer the following questions. Also write at least 10 examples of your own.