How is a trapezoid similar to a parallelogram

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

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)