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Resources: Tensegrity
Icosahedron

Resources: Building polyhedra | tensegrity: icosahedron  | matematicasVisuales
Resources: Building polyhedra | tensegrity: icosahedron | matematicasVisuales
Resources: Building polyhedra | tensegrity: icosahedron | matematicasVisuales


The following construction is a mix between the traditional building of an icosahedron with three golden rectangles and a tensegrity. We used cardboard from a tetrabrik because during the pandemic it was not easy to find other matherials.

Building an icosahedron with three golden rectangles (Spanish) |matematicasVisuales
Building an icosahedron with three golden rectangles (Spanish)
A proposal to build an icosahedron using cardboard from a tetrabrik. (Lots of images).


In the following tensegrity I print the vertices of the golden rectangles using a 3d printer. The three rectangles were made using plastic tubes.

Resources: The golden rectangle and the icosahedron |matematicasVisuales
Resources: The golden rectangle and the icosahedron |matematicasVisuales
Resources: The golden rectangle and the icosahedron |matematicasVisuales
Resources: The golden rectangle and the icosahedron |matematicasVisuales


More constructions of the icosahedron in the following link:

Resources: The golden rectangle and the icosahedron
With three golden rectangles you can build an icosahedron.


Cuboctahedron

The cuboctahedron has four hexagonal sections. The twelve vertices of the cuboctahedron are vertices of these four hexagons.

The volume of a cuboctahedron
A cuboctahedron is an Archimedean solid. It can be seen as made by cutting off the corners of a cube.
The volume of a cuboctahedron (II)
A cuboctahedron is an Archimedean solid. It can be seen as made by cutting off the corners of an octahedron.

We can consider four equilateral triangles that contains the twelve vertices of the cuboctahedron.

Then, we can build the following tensegrity:

Resources: Tensegrity |matematicasVisuales
Resources: Tensegrity |matematicasVisuales

I used a 3d printer to build the vertices and plastic tubes for the edges.

Resources: Tensegrity |matematicasVisuales
Resources: Tensegrity |matematicasVisuales



Five tetrahedra inscribed in a dodecahedron

We can inscribe five tetrahedra in a dodecahedron and build the following tensegrity:



Five tetraedra inscribed in a dodecahedron (Spanish). |matematicasVisuales

This beautiful structure can be built using more techniques. The relation between the dodecahedron, the cube and the tetrahedron can justify why this construction is possible.

Five tetraedra inscribed in a dodecahedron (Spanish).
Different techniques to build five tetraedra inside a dodecahedron: carboard, origami, tensegrity.
Tetrahedron
Resources: Building polyhedra | tensegrity: tetrahedron | matematicasVisuales
Resources: Tensegrity |matematicasVisuales

I found this model in the wonderful site of Marcelo Pars about tensegrity.

More tensegrities

MORE LINKS

Resources: Building Polyhedra with cardboard (Plane Nets)
Using cardboard you can draw plane nets and build polyhedra.
Resources: How to build polyhedra using paper and rubber bands
A very simple technique to build complex and colorful polyhedra.
Resources: Building polyhedra gluing faces
Using cardboard you can build beautiful polyhedra cutting polygons and glue them toghether. This is a very simple and effective technique. You can download several templates. Then print, cut and glue: very easy!
Resources: Building polyhedra gluing discs
Simple technique to build polyhedra gluing discs made of cardboard or paper.
Resources: Acona Biconbi, designed by Bruno Munari
Italian designer Bruno Munari conceived 'Acona Biconbi' as a work of sculpture. It is also a beautiful game to play with colors and shapes.
Resources: The golden rectangle and the icosahedron
With three golden rectangles you can build an icosahedron.
Resources: Modular Origami
Modular Origami is a nice technique to build polyhedra.
Building polyhedra. Basic techniques: Taller de Talento Matemático de Zaragoza (Spanish)
Material for a session about polyhedra (Zaragoza, 13th Abril 2012).
Construcción de poliedros. Cuboctaedro y dodecaedro rómbico: Taller de Talento Matemático de Zaragoza 2014 (Spanish)
Material for a session about polyhedra (Zaragoza, 9th May 2014). Simple techniques to build polyhedra like the tetrahedron, octahedron, the cuboctahedron and the rhombic dodecahedron. We can build a box that is a rhombic dodecahedron.
Cube, octahedron, tetrahedron and other polyhedra: Taller de Talento Matemático Zaragoza,Spain, 2014-2015 (Spanish)
Material for a session about polyhedra (Zaragoza, 7th November 2014). We study the octahedron and the tetrahedron and their volumes. The truncated octahedron helps us to this task. We build a cubic box with cardboard and an origami tetrahedron.
Duality: cube and octahedron. Taller de Talento Matemático de Zaragoza, Spain. 2015-2016 XII edition (Spanish)
Material for a session about polyhedra (Zaragoza, 23rd Octuber 2015) . Building a cube with cardboard and an origami octahedron.
The Cuboctahedron and the truncated octahedron. Taller de Talento Matemático de Zaragoza, Spain. 2016-2017 XIII edition (Spanish)
Material for a session about polyhedra (Zaragoza, 21st October 2016). Instructions to build several geometric bodies.
Microarquitectura and polyhedra (Spanish)
Microarquitectura is a construction game developed by Sara San Gregorio. You can play and build a lot of structures modelled on polyhedra.
The icosahedron and its volume
The twelve vertices of an icosahedron lie in three golden rectangles. Then we can calculate the volume of an icosahedron
The volume of the tetrahedron
The volume of a tetrahedron is one third of the prism that contains it.
Plane developments of geometric bodies: Tetrahedron
The first drawing of a plane net of a regular tetrahedron was published by Dürer in his book 'Underweysung der Messung' ('Four Books of Measurement'), published in 1525 .
Plane developments of geometric bodies (1): Nets of prisms
We study different prisms and we can see how they develop into a plane net. Then we explain how to calculate the lateral surface area.
Plane developments of geometric bodies (3): Cylinders
We study different cylinders and we can see how they develop into a plane. Then we explain how to calculate the lateral surface area.
Plane developments of geometric bodies (5): Pyramid and pyramidal frustrum
Plane net of pyramids and pyramidal frustrum. How to calculate the lateral surface area.
Plane developments of geometric bodies (7): Cone and conical frustrum
Plane developments of cones and conical frustum. How to calculate the lateral surface area.
Plane developments of geometric bodies: Dodecahedron
The first drawing of a plane net of a regular dodecahedron was published by Dürer in his book 'Underweysung der Messung' ('Four Books of Measurement'), published in 1525 .