Tetragon
From Memory Alpha, the free Star Trek reference
A tetragon is a polygon with four sides and four vertices. A square is an example of a tetragon, though tetragons do not need to have sides of equal length.
In 2376, one of Naomi Wildman's geometry lessons was to build a tetragon using everyday objects, rather than using a replicator. She eventually decided on using carrots and celery. (VOY: "Memorial")
