Thursday, January 19, 2017


3d Polyfelt provides a good way to make polyhedral surfaces, calculate its Euler characteristic, study curvature at vertices computing their angular defects, etc.

Pictures below are from the workshop held at the ICME-13. All these figures have the Euler characteristic of a torus, i.e. V-E+F=0.

Torus inspired by triangulation found by Sarah-Marie Belcastro

This torus has 42 faces (12 pentagons, 24 hexagons and 6 octagons), 126 edges, and 84 vertices, which gives you Euler characteristic V-E+F=0.

Here are some more simple toroids with hexagons, octagons, decagons, and squares:

Can you make others? Send us and will be published here!

Some references:

Thursday, December 24, 2015


Investigate which of these nets give a cube. You can buy this puzzle in our Shop online

See solutions of this puzle here:

Thursday, October 1, 2015


Small 3D Polyfelt is already available with new geometrical puzzles! 

You will be able to assemble and disassemble lots of tillings, 3d figures and many other invented objects, in family or at school with classmates.

The game has been tested with great success in many schools and congresses of mathematics education.



Here is a list of figures that can be built with regular polygons:
  1. Platonic solids;
  2. Archimedean solids;
  3. Jhonson solids;
  4. Uniform polyhedra;
  5. Zonohedra; list of zonohedra by Georg Hart
  6. Regularsemiregular and demiregular tilings;
  7. Many other original objects (dresses, decorative objects, etc.). 

Sets available in our Shop online 

Basic set (38 pieces) - 25 eur
20 triangles, 6 squares, 12 pentagons. Can be of different colours.

Medium set (58 pieces) - 35 eur
20 triangles, 18 squares, 12 pentagons, and 8 hexagons.

Big set (108 pieces) - 55 eur
40 triangles, 30 squares, 12 pentagons, 20 hexagons, and 6 octagons.

Extra:  (18 pieces) - 20 eur
12 Decagons + 6 Dodecagons

Full set: Big set + extra (126 pieces) - 75 eur
40 triangles, 30 squares, 12 pentagons, 20 hexagons, 6 octagons, 12 decagons, and 6 dodecagons.

Each set includes a table of 2d and 3d figures

You can also have a look at our collaborative list of figures with solutions (under construction).

Other packs of polygons, colors, and shapes are available under request.

© 2016 3D Polyfelt - Polifieltros 3D ®. All rights reserved.

Saturday, February 28, 2015


3d Polyfelt workshop during the celebration of the Andalucian Day, February 28th, at primary school CEIP San Fernando, Almería.

You can find more information about "truncation" of polyhedra and tillings here

Like our facebook page to see news and more pictures:

Wednesday, April 23, 2014


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.

Wednesday, April 2, 2014


Today, some students of the IES Francisco Montoya, from Las Norias (Almería) have constructed the 2nd iteration of the Menger sponge, with the help of their math teacher Lidia García. They have used 1056 squares, 176 squares per 6 colours, one for each face. They have spent about 3 hours to complete it. Really cool and funny!

This project, started with David Crespo as explained in this post, will be presented at the XII Feria de la Ciencia de Sevilla together with many other manipulative games with fractals.

You can see it these days in the hall of the school center!

Tuesday, April 1, 2014