parallelogram vs quadrangle

parallelogram and quadrangle both are nouns.

Word	Noun	Adjective	Verb	Adverb
parallelogram	Yes	No	No	No
quadrangle	Yes	No	No	No

As nouns, quadrangle is a hypernym of parallelogram; that is, quadrangle is a word with a broader meaning than parallelogram:

parallelogram: a quadrilateral whose opposite sides are both parallel and equal in length
quadrangle: a four-sided polygon

Other hypernyms of parallelogram include quadrilateral, tetragon.

parallelogram (noun)	quadrangle (noun)
a quadrilateral whose opposite sides are both parallel and equal in length	a rectangular area surrounded on all sides by buildings
	a four-sided polygon