Try Our Apps


Fall Head Over Heels...

right angle

the angle formed by two radii of a circle that are drawn to the extremities of an arc equal to one quarter of the circle; the angle formed by two perpendicular lines that intersect; an angle of 90°.
Origin of right angle
1350-1400; Middle English
Related forms
right-angled, adjective Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2016.
Cite This Source
Examples from the Web for right-angle
Contemporary Examples
Historical Examples
  • The pipe entered through the end of the tunnel, threaded into a right-angle pipe fitting, and disappeared into the tunnel floor!

    The Blue Ghost Mystery Harold Leland Goodwin
  • Obtuse, an angle having a wider opening than a right-angle or "perpendicular."

    Stained Glass Work C. W. Whall
  • At length he rose and climbed on, presently turning at a right-angle to bisect the strip to its boundary before he paused to rest.

    The Valiants of Virginia Hallie Erminie Rives
  • At the epicentre, the angle of emergence is a right-angle; at a great distance from the epicentre, it is nearly zero.

  • That one side and one acute angle of a right-angle triangle determine the other sides of the triangle.

  • Its bole, five feet of stalwart diameter, rose straight and tapering to the first right-angle limbs, each in itself almost a tree.

    The Roof Tree Charles Neville Buck
  • Fig. 245 shows a form of right-angle cross which allows the trolley-wheels of crossing lines to pass.

    Things a Boy Should Know About Electricity Thomas M. (Thomas Matthew) St. John
  • The toe is never pointed in line with the leg, but held at a right-angle to it, as in the standing position.

    The Morris Book Cecil J. Sharp
British Dictionary definitions for right-angle

right angle

the angle between two radii of a circle that cut off on the circumference an arc equal in length to one quarter of the circumference; an angle of 90° or π/2 radians
at right angles, perpendicular or perpendicularly
adjective orthogonal
Derived Forms
right-angled, adjective
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Cite This Source
right-angle in Science
right angle
An angle having a measure of 90°.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source
right-angle in Culture

right angle definition

An angle measuring ninety degrees, formed by the intersection of two perpendicular lines. (Compare acute angle and obtuse angle.)

The American Heritage® New Dictionary of Cultural Literacy, Third Edition
Copyright © 2005 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
Cite This Source

Word of the Day

Difficulty index for right angle

Few English speakers likely know this word

Word Value for right

Scrabble Words With Friends

Nearby words for right-angle