Wolfram Demonstrations Projecthttp://demonstrations.wolfram.com/An Open Resource of Interactive Mathematica VisualizationsCopyright 2009 Wolfram Demonstrations Project & ContributorsCalculating Area, Perimeter, and Diagonal Length of a Rectanglehttp://demonstrations.wolfram.com/CalculatingAreaPerimeterAndDiagonalLengthOfARectangle/]]>http://demonstrations.wolfram.com/CalculatingAreaPerimeterAndDiagonalLengthOfARectangle/Rectangles: Perimeter and Areahttp://demonstrations.wolfram.com/RectanglesPerimeterAndArea/]]>http://demonstrations.wolfram.com/RectanglesPerimeterAndArea/Covering the Plane with Polygonshttp://demonstrations.wolfram.com/CoveringThePlaneWithPolygons/]]>http://demonstrations.wolfram.com/CoveringThePlaneWithPolygons/Divisors of a Numberhttp://demonstrations.wolfram.com/DivisorsOfANumber/]]>http://demonstrations.wolfram.com/DivisorsOfANumber/