Segment Addition Postulate

Pronunciation: /ˈsɛg.mənt əˈdɪ.ʃən ˈpɑs.tʃə.lət/ Explain

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Place the middle point on the line between A and B. Is C between A and B?
Manipulative 1 - Segment Addition Postulate Created with GeoGebra.

The segment addition postulate states that given three points A, B and C on a line, C is between A and B if and only if AC + CB = AB. If C lies between A and B, then the sum of AC and CB equals AB. Also, if the sum of AC and CB equals AB, then C lies between A and B.

This postulate defines what it means to say "Point C is between point A and point B." If point C is not on the same line as AB, then the distance of AC plus CB is always greater than AB. So, a point can not be between two other points unless it is on the same line as the other points. If C is on the same line as A and B, but lies outside of A and B, then AC + CB > AB.

More Information

  • McAdams, David E.. Between. allmathwords.org. All Math Words Encyclopedia. Life is a Story Problem LLC. 3/16/2010. http://www.allmathwords.org/en/b/between.html.

Cite this article as:

McAdams, David E. Segment Addition Postulate. 12/21/2018. All Math Words Encyclopedia. Life is a Story Problem LLC. http://www.allmathwords.org/en/s/segmentadditionpostulate.html.

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Revision History

12/21/2018: Reviewed and corrected IPA pronunication. (McAdams, David E.)
12/6/2018: Removed broken links, updated license, implemented new markup, implemented new Geogebra app. (McAdams, David E.)
5/5/2011: Initial version. (McAdams, David E.)

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