Parallelogram

Pronunciation: /ˌpær əˈlɛl əˌgræm/ ?

Sorry, the GeoGebra Applet could not be started. Please make sure that Java 1.4.2 (or later) is installed and active in your browser (Click here to install Java now) Manipulative 1: Parallelogram. Created with GeoGebra.

A parallelogram is a four sided polygon whose opposite sides are parallel.[1][2] Click on the blue points in manipulative 1 and drag them to change the figure. No matter where you drag them, the figure is a parallelogram.

Properties of Parallelograms

Sorry, the GeoGebra Applet could not be started. Please make sure that Java 1.4.2 (or later) is installed and active in your browser (Click here to install Java now) Manipulative 2: Parallelogram. Created with GeoGebra.

Click on the blue points in manipulative 2 and drag them to change the figure. Click on the checkboxes to see the respective properties demonstrated. The opposite angles of a parallelogram are congruent. The opposite sides of a parallelogram are congruent and parallel. The diagonals bisect each other. Each diagonal bisects the parallelogram into two congruent triangles. The sums of the angles of a parallelogram is 360° or 2π radians. A tesselation of a plane can be created using any parallelogram. The area of a parallelogram is A = bh where A is the area, b is the base and h is the height.

References

1. Hilbert, David. The Foundations of Geometry, pp 28,33-35. Townsend, E. J., Ph. D.. The Open Court Publishing Company, 1950. (Accessed: 2009-12-21). http://www.gutenberg.org/files/17384/17384-pdf.pdf.
2. Stöcker, K.H.. The Elements of Constructive Geometry, Inductively Presented, pp 23, 32-33. Translated by Noetling, William A.M, C.E.. Silver, Burdett & Company, 1897. (Accessed: 2009-12-30). http://www.archive.org/stream/elementsofconstr00noetrich#page/23/mode/1up/search/parallelogram.
3. Keller, Samuel Smith. Mathematics for Engineering Students, Plane and Solid Geometry, pp 44, 34-36, 72-73. D. Van Nostrand Company, 1908. (Accessed: 2010-01-02). http://www.archive.org/stream/firstsixbooksofe00caseuoft#page/44/mode/1up/search/parallelogram.
4. parallelogram. http://wordnet.princeton.edu/. WordNet. Princeton University. (Accessed: 2011-01-08). http://wordnetweb.princeton.edu/perl/webwn?s=parallelogram&sub=Search+WordNet&o2=&o0=1&o7=&o5=&o1=1&o6=&o4=&o3=&h=.

Cite this article as:

Parallelogram. 2009-12-21. All Math Words Encyclopedia. Life is a Story Problem.org. http://www.allmathwords.org/en/p/parallelogram.html.

Translations

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Image Credits

• All images and manipulatives are by David McAdams unless otherwise stated. All images by David McAdams are Copyright © Life is a Story Problem.org and are licensed under the Creative Commons Attribution-Noncommercial-Share Alike 3.0 License.

Revision History

2009-12-21: Added "References" (McAdams, David.)
2008-10-24: Initial version (McAdams, David.)