Meshuribul (משוריבול)

This is a Mesuribul (משוריבול). It's a circle. It's a triangle. It's a square. It all depends on your point of view.

You can watch a very old educational video (in Hebrew) featuring the Meshuribul (משוריבול) : https://youtu.be/lgZtuGgAZvo?t=1175