How is a rectangle and a trapezoid similar

Both have 4 sides.

And off those four sides one side is equal to and parallel to one other side, the remaining sides are equal to each other and are longer or shorter than the first two.

Here's one for you nadya11, you may already know the answer, but my classes always love taking this one home to see if their parents can figure it out!

How can a square be a rectangle but a rectangle can not be a square? :)