the defenition of a trapezoid is only 1 pair of paralell sides
a paralellogram is defined as having 2 pairs of paralell sides
therefor a trapezoid cannot be a paralellogram
rectangles, rhombuses and squares are all paralellograms
since trapezoid≠paralellograms and
rectanges&rhombuses&squares=paralellograms
therfor trapezoids≠rectanges&rhombuses&squares