- rectangular - having four right angles; "a rectangular figure twice as long as it is wide"
Antonym: rounded (indirect, via angular)
- orthogonal, rectangular - having a set of mutually perpendicular axes; meeting at right angles; "wind and sea may displace the ship's center of gravity along three orthogonal axes"; "a rectangular Cartesian coordinate system"
Antonym: oblique (indirect, via parallel, perpendicular)
Antonym: parallel (indirect, via perpendicular, oblique)