Many objects in real life are based on geometric construction. It could be art e.g. graphics or drawing, letters in a geometric style, a turning windmill as well as crop circles or plan of games , tangrams ... 

So they can be modeled or movements can be simulated using GeoGebra. 

Common project 2: puzzle factory  - digital tangrams -> GO HERE

Common project 1: Movements in Real Life -> GO HERE

Project 3: Crop circles (GER) -> GO HERE