Definition: In Euclidean geometry, a parallelogram is a convex quadrilateral with two pairs of parallel sides. The opposite or facing sides of a parallelogram are of equal length and the opposite angles of a parallelogram are of equal measure. The congruence of opposite sides and opposite angles is a direct consequence of the Euclidean Parallel Postulate and neither condition can be proven without appealing to the Euclidean Parallel Postulate or one of its equivalent formulations. The three-dimensional counterpart of a parallelogram is a parallelepiped.
The etymology (in Greek ????????-????????, a shape “of parallel lines”) reflects the definition.
theorems for a parallelogram
not a triangle
a method of vector resolution
area of a parallellogram
Please post the direct URL (link) where your drawing, doodle, artwork is posted (e.g. your blog, Flickr) in the comments area of this post. I would really like to keep all the artwork together and provide a way for others to see your work and/or your blog, and how your work relates to the other responses.
The Creative Prompt Project, also, has a Flickr group, which you can join to post your responses. Are you already a member? I created that spot so those of you without blogs and websites would have a place to post your responses. Please join and look at all of the great artwork that people have posted.