find the area of trapezium whose parallel sides are 30 cm and 12 cm long , and the distance between them is 16 cm ?
"area of a trapezium = 1 / 2 ( sum of parallel sides ) * ( perpendicular distance between them ) = 1 / 2 ( 30 + 12 ) * ( 16 ) = 336 cm 2 answer : d"
quadrilateral_area(16, 12, 30)