To all users of 3DPolyfelt, here is a simple puzzle:
How to make a tetrahedron with these 6 pieces of 3DPolyfelt?
It is important to consider the male and female joins of velcro correctly.
SOLUTION: Thanks to Raul Ibáñez, winner of the Edición 3.4 Emmy Noether, del Carnaval de Matemáticas, for inspiring the solution to this puzzle, and congratulations for this price.