The diagram shows the universal set u = {parallelograms}. set a represents parallelograms with four congruent sides, while set b represents parallelograms with four congruent angles. how many of the parallelograms fall into the category a b?

U  ={ Parallelograms}

A= { Parallelogram with four congruent sides}={ Rhombus,Square}

B ={ Parallelograms with four congruent angles} ={ Rectangle, Square}

So, AB= { Square}

So among all the parallelograms "Square" is the only parallelogram which has all congruent sides as well as all congruent angles.

answer:

sometimes

*i think

this is false ^.^ lol