Obtuse Triangle
Pronunciation: /əbˈtus ˈtraɪˌæŋ.gəl/ Explain
Figure 1: Obtuse triangle 

An obtuse triangle is a
triangle
where one of the angles is an
obtuse angle.^{[1]}
An obtuse angle is an angle with a measure of more than
90° (π radians).
See figure 1.
Since all triangles that do not have a right angle are scalene triangles, all obtuse
triangles are also obtuse scalene triangles.

Click on the blue point and drag it to change the figure.
This manipulative will only show obtuse triangles. What definition can you give for obtuse triangles?
 Manipulative 1  Obtuse Triangle Created with GeoGebra. 

References
 McAdams, David E.. All Math Words Dictionary, obtuse triangle. 2nd Classroom edition 201501084799968. pg 129. Life is a Story Problem LLC. January 8, 2015. Buy the book
 Casey, John, LL.D., F.R.S.. The First Six Books of the Elements of Euclid. pg 8. Translated by Casey, John, LL. www.archive.org. D. F.R.S.. Hodges, Figgis & Co.. 1890. Last Accessed 9/5/2018. http://www.archive.org/stream/firstsixbooksofe00caseuoft#page/8/mode/1up/search/obtuse. Buy the book
More Information
 McAdams, David E.. Obtuse Angle. allmathwords.org. All Math Words Encyclopedia. Life is a Story Problem LLC. 3/12/2009. http://www.allmathwords.org/en/o/obtuseangle.html.
Cite this article as:
McAdams, David E. Obtuse Triangle. 12/21/2018. All Math Words Encyclopedia. Life is a Story Problem LLC. http://www.allmathwords.org/en/o/obtusetriangle.html.
Image Credits
Revision History
12/21/2018: Reviewed and corrected IPA pronunication. (
McAdams, David E.)
9/5/2018: Removed broken links, updated license, implemented new markup. (
McAdams, David E.)
12/21/2009: Added "References". (
McAdams, David E.)
8/26/2008: Revised references to 'scalene' and revised 'More Information'. (
McAdams, David E.)
7/12/2007: Initial version. (
McAdams, David E.)