• Area Builder from PhET illustrates the relationship between perimeter and area

https://phet.colorado.edu/sims/html/area-builder/latest/area-builder_en.html

 

Two useful simulations from JavaLab

 

  • Hyperpaint allows you to illustrate drawing on a hyperbolic surface

https://editor.p5js.org/zokalyx/full/ESz3r4_Tu