www.mathisfun.com/geometry
http://en.wikipedia.org/wiki/File:Isosceles_trapezoid.jpg
http://www.icoachmath.com/math_dictionary/Intersecting_Lines.html
http://en.wikipedia.org/wiki/File:Isosceles_trapezoid.jpg
http://www.icoachmath.com/math_dictionary/Intersecting_Lines.html