Straight Angle

Pronunciation: /streɪt 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 span class="keyword">straight angle is an angle that measures 1/2 of a full circle.[2] Classes of Angles Degree Measure Radian Measure Class Name α < 90° α < π / 2 rad. Acute angle α = 90° α = π / 2 rad. Right angle 90° < α < 180° π / 2 < α < π rad. Obtuse angle α = 180° α = π rad. Straight angle 180 < α < 360° π < α < 2π rad. Reflex angle α = 360° α = 2π rad. Full angle Table 1: Classes of angles

References

1. McAdams, David E.. All Math Words Dictionary, straight angle. 2nd Classroom edition 20150108-4799968. pg 171. Life is a Story Problem LLC. January 8, 2015. Buy the book
2. Keller, Samuel Smith. Mathematics for Engineering Students, Plane and Solid Geometry. pg 2. www.archive.org. D. Van Nostrand Company. 1908. Last Accessed 12/13/2018. http://www.archive.org/stream/mathengineer00kellrich#page/2/mode/1up/search/straight. Buy the book
3. Hilbert, David. The Foundations of Geometry. pp 18-19. Translated by Townsend, E. J., Ph. D.. The Open Court Publishing Company. 1950. Last Accessed 12/13/2018. http://www.gutenberg.org/files/17384/17384-pdf.pdf. Buy the book

Cite this article as:

McAdams, David E. Straight Angle. 5/7/2019. All Math Words Encyclopedia. Life is a Story Problem LLC. http://www.allmathwords.org/en/s/straightangle.html.

Image Credits

• All images and manipulatives are by David McAdams unless otherwise stated. All images by David McAdams are Copyright © Life is a Story Problem LLC and are licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.

Revision History

5/7/2019: Changed equations and expressions to new format. (McAdams, David E.)
12/21/2018: Reviewed and corrected IPA pronunication. (McAdams, David E.)
12/10/2018: 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.)
5/5/2011: Initial version. (McAdams, David E.)