Right Angle
Pronunciation: /raɪt ˈæŋ.gəl/ Explain
Click on the blue point and drag it to change the figure.
Can you find all 5 angle classes represented?
 Manipulative 1  Angle Classes Created with GeoGebra. 

Angles
are divided into four classes according to their measure. A
right angle is an angle that measures 1/4 of
a full circle^{[1]}.

References
 Keller, Samuel Smith. Mathematics for Engineering Students, Plane and Solid Geometry. pg 2. www.archive.org. D. Van Nostrand Company. 1908. Last Accessed 12/4/2018. http://www.archive.org/stream/mathengineer00kellrich#page/2/mode/1up/search/right. Buy the book
 Casey, John, LL.D., F.R.S.. The First Six Books of the Elements of Euclid. pg 7. Translated by Casey, John, LL.D. F.R.S.. www.archive.org. Hodges, Figgis & Co.. 1890. Last Accessed 12/4/2018. http://www.archive.org/stream/firstsixbooksofe00caseuoft#page/7/mode/1up/search/right. Buy the book
 right angle. merriamwebster.com. Encyclopedia Britannica. MerriamWebster. Last Accessed 12/4/2018. http://www.merriamwebster.com/dictionary/right angle. Buy the book
Educator Resources
Cite this article as:
McAdams, David E. Right Angle. 12/21/2018. All Math Words Encyclopedia. Life is a Story Problem LLC. http://www.allmathwords.org/en/r/rightangle.html.
Image Credits
Revision History
12/21/2018: Reviewed and corrected IPA pronunication. (
McAdams, David E.)
12/5/2018: Removed broken links, updated license, implemented new markup, implemented new Geogebra app. (
McAdams, David E.)
8/7/2018: Changed vocabulary links to WORDLINK format. (
McAdams, David E.)
1/1/2010: Added "References". (
McAdams, David E.)
12/14/2009: Added reference to Euclid's Elements. Expanded table of angle classes. (
McAdams, David E.)
9/16/2008: Initial version. (
McAdams, David E.)