LSJ
τό, rectangle, Arist. de An. 413a17 ; ὀρθογώνιος, ον, rectangular, Archyt. ap. Simp. in Cat. 392.8 ; τρίγωνον Ti.Locr. 98a, D.L. 8.12 ; κῶνος Archim. Sph. Cyl. 1 Prooem. ; ἐξ ὀρθογωνίου by rectangular measurement, PSI 4.320.12 (i AD), POxy. 2134.15 (ii AD).
Liddell-Scott-Jones, Greek-English Lexicon (9th ed., 1940)