find the area of trapezium whose parallel sides are 18 cm and 12 cm long , and the distance between them is 14 cm ?
"area of a trapezium = 1 / 2 ( sum of parallel sides ) * ( perpendicular distance between them ) = 1 / 2 ( 18 + 12 ) * ( 14 ) = 224 cm 2 answer : c"
quadrilateral_area(14, 12, 18)