Common Tangents

Pronunciation: /ˈkɒm ən ˈtæn dʒəntz/ ?

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Manipulative 1: Tangent lines to two circles.

Each pair of circles in a plane have two tangent lines in common. These tangent lines are called common tangents of the circles.

Manipulative 1 sows common tangents for two circles. Click on the blue points and drag them change the figure. Double click on the manipulative to open the figure full screen.


  1. common tangent. McGraw-Hill Dictionary of Scientific and Technical Terms. McGraw-Hill Companies, Inc., 1974. (Accessed: 2010-01-27).
  2. Shlomo Libeskind. Euclidean and Transformational Geometry: A Deductive Inquiry, pp 110-112. Jones & Bartlett Publishers, November 1, 2007. (Accessed: 2010-01-27).
  3. Ray C. Jurgensen, Richard G. Brown, and John W. Jurgensen. Geometry, pg 334. Houghton Mifflin McDougal Littell, January 2000.

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Cite this article as:

Common Tangents. 2010-01-27. All Math Words Encyclopedia. Life is a Story Problem LLC.

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Revision History

2010-01-27: Initial version (McAdams, David.)

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