Parallelogram
Pronunciation: /ˌpær əˈlɛl əˌgræm/ Explain
 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
 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 tessellation 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
 Hilbert, David. The Foundations of Geometry. pp 28,3335. Translated by Townsend, E. J., Ph. D.. The Open Court Publishing Company. 1950. Last Accessed 12/21/2009. http://www.gutenberg.org/files/17384/17384pdf.pdf.
 Stöcker, K.H.. The Elements of Constructive Geometry, Inductively Presented. pp 23, 3233. Translated by Noetling, William A.M, C.E.. www.archive.org. Silver, Burdett & Company. 1897. Last Accessed 12/31/2009. http://www.archive.org/stream/elementsofconstr00noetrich#page/23/mode/1up/search/parallelogram. Buy the book
 Keller, Samuel Smith. Mathematics for Engineering Students, Plane and Solid Geometry. pp 44, 3436, 7273. www.archive.org. D. Van Nostrand Company. 1908. Last Accessed 1/2/2010. http://www.archive.org/stream/firstsixbooksofe00caseuoft#page/44/mode/1up/search/parallelogram. Buy the book
Cite this article as:
McAdams, David E. Parallelogram. 8/28/2018. All Math Words Encyclopedia. Life is a Story Problem LLC. http://www.allmathwords.org/en/p/parallelogram.html.
Image Credits
Revision History
8/28/2018: Corrected spelling. (
McAdams, David E.)
8/7/2018: Changed vocabulary links to WORDLINK format. (
McAdams, David E.)
12/21/2009: Added "References". (
McAdams, David E.)
10/24/2008: Initial version. (
McAdams, David E.)