Question

How is a trapezoid similar to a parallelogram

Answer 1

They both have four sides, and they both have at least one pair of sides that are parallel.

Answer 2

Trapezoid and paralellogram are both quadrilaterals

the heiarchy is
quadrilaterals are 4 sided figures
quadrilaterals is split up into
      A. no pairs of paralell sides
             - kite
       B. 1 pair of paralell sides
               - trapezoid/trapezium
      C. 2 pairs of parell sides (paralellograms)
           -rectangles
           -rhombus
           -square


so you can see that they are both quadrilaterals (quad=4, lateral=sides, quadrilateral=4 sided figure)