David Butler's new Quarter the cross challenge contains a link to all of his writing about it. https://blogs.adelaide.edu.au/maths-learning/2020/11/15/quarter-the-cross-connect-the-dots/[br][br]I've used this with kids, preservice teachers and calculus students, but somehow never made GeoGebra for it. Don't limit yourself to polygons, but this is a start!