A rectangle of the greatest area is inscribed in a trapezium `A B C D` , one of whose non-parallel sides `A B` is perpendicular to the base, so that one of the rectangles die lies on the larger base of the trapezium. The base of trapezium are 6cm and 10 cm and `A B` is 8 cm long. Then the maximum area of the rectangle is `24c m^2` (b) `48c m^2` `36c m^2` (d) none of these