Wolfram Demonstrations Projecthttp://demonstrations.wolfram.com/An Open Resource of Interactive Mathematica VisualizationsCopyright 2009 Wolfram Demonstrations Project & ContributorsAreas of Parallelograms and Trapezoidshttp://demonstrations.wolfram.com/AreasOfParallelogramsAndTrapezoids/]]>http://demonstrations.wolfram.com/AreasOfParallelogramsAndTrapezoids/Calculating 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/Estimating Perimeter and Area of Simple Polygonshttp://demonstrations.wolfram.com/EstimatingPerimeterAndAreaOfSimplePolygons/]]>http://demonstrations.wolfram.com/EstimatingPerimeterAndAreaOfSimplePolygons/The Area of a Triangle as Half a Rectanglehttp://demonstrations.wolfram.com/TheAreaOfATriangleAsHalfARectangle/]]>http://demonstrations.wolfram.com/TheAreaOfATriangleAsHalfARectangle/Areas of Triangleshttp://demonstrations.wolfram.com/AreasOfTriangles/]]>http://demonstrations.wolfram.com/AreasOfTriangles/Areas of Parallelogramshttp://demonstrations.wolfram.com/AreasOfParallelograms/]]>http://demonstrations.wolfram.com/AreasOfParallelograms/