# Stellated Icosaedron Hat

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Have you ever disguised yourself as platonic solids? I do! I used cardboard, white glue,cutter, an icosahedron template, a tetrahedron template and glitter foam.

### Teacher Notes

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## Step 1: Drawing the Icosaedron Template on the Cardboard

To start you need a large cardboard on which to draw an icosahedron template (you can find printable templates on the internet). It is advisable that the triangles of the icosahedron have about 15 cm per side. After drawing the template on the cardboard you have to cut with a cutter. Do not forget to leave a margin in some triangles to fold and paste!

## Step 2: Constructing the Icosaedron

Fold the cardboard along the lines of each triangle and glue the margins you left behind with a white glue. Very important! Leave the bottom 5 triangles unglued. It is where you will put your head!

## Step 3: Building Tetrahedra

Now you have to build 15 cardboard tetrahedra. (you will find templates on the internet) Important! The tetrahedra should be the same size as the sides of the icosahedron (15cm).

## Step 4: Decorating

You have 1 cardboard icosahedron and 15 cardboard tetrahedra. Now we are going to decorate the tretrahedrons before sticking them to the icosahedron. We will use glitter foam and white glue. The tetrahedrons must be decorated on 3 sides. The fourth face is left in cardboard to glue each tetrahedron to a face of the icosahedron.

## Step 5: Inside

The hardest part for me was to finish the inside of the hat. My solution was to cut a cardboard pentagon of 15 cm per side with margins to fold and glue it inside. Then I glued some foams on each side to make the hole smaller and more comfortable.

## Step 6: Finished!

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## Discussions

Fun!
Good idea to use foam sponges on the inside to make the hat fit.