I have a piece in today’s TES Magazine about using dynamic geometry software for exploring symmetry on an interactive whiteboard:
The lesson starts with a little mental arithmetic, but soon turns into interactive geometry using a computer, projector and input device. It works well on an interactive whiteboard. But you could just use a wireless mouse, which is easier to manage because it can be passed round the class without the need for pupils to come to up to the board.
You’ll also need some dynamic geometry software. The commercial leaders are Geometer’s Sketchpad and Cabri, both of which run on Mac and Windows; GeoGebra and Kig are good open source alternatives. GeoGebra will run happily inside a learning platform as well as on a desktop.