This applet supports the Common Core State Standards for Mathematics Content. The Standard represented is 6.G.A.1, which states: "Find the area of right triangles, other triangles, special quadrilaterals, and polygons by composing into rectangles or decomposing into triangles and other shapes; apply these techniques in the context of solving real-world and mathematical problems" (Source: http://www.corestandards.org/Math )