Law of Sines

Pronunciation: /lɔ ʌv saɪnz/ Explain

The law of sines relates the angles of a triangle to the length of the opposite sides: sin(a)/a=sin(b)/b=sin(c)/c

When the measures of two angles and a side are known, the law of sines provides a way to calculate the other sides and the remaining angle. This is called triangulation.

Click on the blue points and drag them to change the figure.

Is there any way you can change the triangle so that the three values are not equal?
Manipulative 1 - Law of Sines Created with GeoGebra.


  1. McAdams, David E.. All Math Words Dictionary, law of sines. 2nd Classroom edition 20150108-4799968. pg 106. Life is a Story Problem LLC. January 8, 2015. Buy the book

More Information

  • McAdams, David E.. Triangle. All Math Words Encyclopedia. Life is a Story Problem LLC. 8/31/2018.

Cite this article as:

McAdams, David E. Law of Sines. 12/21/2018. All Math Words Encyclopedia. Life is a Story Problem LLC.

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Revision History

12/21/2018: Reviewed and corrected IPA pronunication. (McAdams, David E.)
8/31/2018: Removed broken links, updated license, implemented new markup, implemented new Geogebra protocol. (McAdams, David E.)
8/28/2018: Initial version. (McAdams, David E.)

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