Sketchpad files... can be modified to work with Geogebra
Angles with Sketchpad
Button Information
Fractals
Parallel Lines
Parallelograms with Sketchpad
Polygon Angles
with Sketchpad
Polygon Area with Sketchpad
Polygon Area
wtih Sketchpad version 2
Sketchpad
Rectangles, Squares, and Rhombi
Triangle Discovery
Vertical Angle Discovery