What theorem is dynamically being illustrated in the applet below?[br](Feel free to alter the locations of the [color=#980000][b]brown vertices[/b][/color] of the white quadrilateral at any time!)
[b][color=#000000]Thebault's Theorem:[/color][/b][br]If squares are built off the sides of a parallelogram, then the [color=#1e84cc][b]centers[/b][/color] of these squares form [color=#1e84cc][b]vertices[/b][/color] of another [color=#ff00ff][b]square[/b][/color]!