Birectangular :: Birectangular (a.) Containing or having two right angles; as, a birectangular spherical triangle..
Rectangle :: Rectangle (n.) A four-sided figure having only right angles; a right-angled parallelogram.
Rectangular :: Rectangular (a.) Right-angled; having one or more angles of ninety degrees.
Rectangularity :: Rectangularity (n.) The quality or condition of being rectangular, or right-angled..