Triangles in a Square

Within a given square, three triangles are constructed as shown in the applet, with no overlapping. What is the combined area of the triangles? How is it related to that of the square?
Triangles in a Square
1) Can you add more triangles in a similar way? [br]2) Can you do the same thing using a rectangle?[br]3) What is the purpose of this type of GeoGebra exploration?

Information: Triangles in a Square