Parallelogram
Four sided figure with parallel lines.
Opposite sides are equal
Opposite angles are equal
Opposite sides never intersect
Links
http://www.mathsisfun.com/quadrilaterals.html
http://www.ies.co.jp/math/products/geo1/applets/para/para.html
http://www.mathopenref.com/parallelogram.html
http://www.mathleague.com/help/geometry/polygons.htm#parallelogram
http://www.mathwarehouse.com/geometry/quadrilaterals/parallelograms/index.php