/ Dictionary / Index R right triangle: Meaning and Definition of Find definitions for: right' tri'angle Pronunciation: [key] a triangle having a right angle (contrasted with oblique triangle). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. right-to-work law rightward Related Content Daily Word Quiz: winsome Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language