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 )
In this applet, you can adjust the height and base of the right triangle and see what happens to the triangle's area.

1. Move the triangle around so the base is not flat to the bottom of the screen. Does this affect the triangle's area?
2. Does it matter which sides of the triangle are considered the "base" and "height" when calculating area?
2. See if you can create a similar applet involving non-right triangles.