8a.Truncated icosahedron  12/5      20/6 from truncation of  icosahedron  20/3

      Data

     The distance from the center of the icosahedron to the center of the icosahedron triangle is EP 0.76. The distance from 

   the center of the truncated  icosahedron to the center of the hexagon is EA 2.27 . These two distances are equal, thus EA

    = EP 1/3.

     Construction

    EP is divided in three equal parts.    

    20 hexagons (red) are applied on the icosahedron triangles. The twelve coners (yellow) are cut off,

    resulting in twelve pentagons (green-blue).

    
   

   

    Line 1. Icosahedron, net and solid.  .

    Line 2. Truncated icosahedron, net and solid

 

     8b.   Truncated icosahedron from truncation of dodecahedron 12/5

       Data

     The distance from the centre of the dodecahedron to the center of  the pentagon is EP1.11. The distance from

      the  centre of the truncated icosahedron to the centre of the pentagon is EA ×2.33

     These two distances are equal, thus EA = EP 0.48

  

    . The distance between the corner of the truncated icosahedron pentagon (red) and

    the midpoint of the dodecahedron pentagon is incircle radius of the dodecahedron pentagon minus circum-circle radius

    of  the truncated icosahedron pentagon ; Ep 0.69 minus EA 0.86 =  EP0.28.

     Construction

    

    The pentagons (red) are applied on the dodecahedron pentagons with the corners directed to

     the midpoint of the dodecahedron pentagon edges

    The twenty corners (yellow) of the dodecahedron  are cut off, resulting in twenty hexagons (green-blue.

   

    Drawing demonstrating the site of the truncated icosahedron pentagon