nd the area of trapezium whose parallel sides are 20 cm and 18 cm long , and the distance between them is 12 cm ?
"area of a trapezium = 1 / 2 ( sum of parallel sides ) * ( perpendicular distance between them ) = 1 / 2 ( 20 + 18 ) * ( 12 ) = 228 cm 2 answer : e"
divide(multiply(12, add(20, 18)), const_2)