Acute Triangle
Pronunciation: /əˈkjut ˈtraɪˌæŋ.gəl/ Explain
Click on the blue points and drag them to change the figure.
What can you say about the triangle when it is an acute triangle?
 Manipulative 1  Acute Triangle Created with GeoGebra. 

An acute triangle is a
triangle where all of the
angles are
acute angles.^{[2]}
An acute angle is an angle with a measure of less than
90° (π/2 radians). Since all triangles that
do not have a
right angle
are scalene triangles,
all acute triangles are also acute scalene triangles.

References
 McAdams, David E.. All Math Words Dictionary, acute triangle. 2nd Classroom edition 201501084799968. pg 10. 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.D. F.R.S.. www.archive.org. Hodges, Figgis & Co., . 1890. Last Accessed 6/12/2018. http://www.archive.org/stream/firstsixbooksofe00caseuoft#page/8/mode/1up/search/acute. Buy the book
 Le Clerc, Sébastien; Nattes, John Claude; . Nattes's practical geometry, or, Introduction to perspective. pg 11. Translated by Pyne, W. H.. www.archive.org. W. Miller. 1890. Last Accessed 6/12/2018. http://www.archive.org/stream/nattesspractical00leclrich#page/11/mode/1up/search/acute. Buy the book
Cite this article as:
McAdams, David E. Acute Triangle. 4/11/2019. All Math Words Encyclopedia. Life is a Story Problem LLC. https://www.allmathwords.org/en/a/acutetriangle.html.
Image Credits
Revision History
4/11/2019: Changed equations and expressions to new format. (
McAdams, David E.)
12/21/2018: Reviewed and corrected IPA pronunication. (
McAdams, David E.)
12/16/2018: Removed extraneous image. (
McAdams, David E.)
6/18/2018: Changed image of acute triangle to manipulative. (
McAdams, David E.)
6/12/2018: Removed broken links, updated license, implemented new markup. (
McAdams, David E.)
5/5/2011: Initial version. (
McAdams, David E.)