Pronunciation: /ɪkˈstɪər.i.ər/ Explain
Interior, exterior and boundary of a triangle
Figure 1: Interior and exterior of a triangle.

An object is on the exterior if it lies outside a boundary.

Click on the blue points and drag them to change the figure. Click on the red points and drag them to explore the interior and exterior.

Is the border of the polygon in the exterior or interior?
Manipulative 1 - Exterior and Interior of a Polygon Created with GeoGebra.


  1. McAdams, David E.. All Math Words Dictionary, exterior. 2nd Classroom edition 20150108-4799968. pg 76. Life is a Story Problem LLC. January 8, 2015. Buy the book

Cite this article as:

McAdams, David E. Exterior. 12/21/2018. All Math Words Encyclopedia. Life is a Story Problem LLC. https://www.allmathwords.org/en/e/exterior.html.

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Revision History

12/21/2018: Reviewed and corrected IPA pronunication. (McAdams, David E.)
7/5/2018: Removed broken links, updated license, implemented new markup, implemented new Geogebra protocol. (McAdams, David E.)
2/3/2010: Added "References". (McAdams, David E.)
4/1/2008: Initial version. (McAdams, David E.)

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