3a.  Truncated octahedron  6/4  8/6 from truncation of cub  6/4

          Data

The distance from the centre of the cube to the centre of the square is EP /2 .

The distance from the centre of the the  truncated octahedron to the centre of the square(red) is  EA×1.41. These two distances are equal, thus EA=EP×0.35       

The distance between the mid-point of the cube square edge and the corner of the 

truncated octahedron square (red) is EP/2 minus EA×Ö2/2   i.e., EP×0.15.

           Construction

The six squares (red) are applied on the cube squares.The eight corners (yellow) are cut off, resulting in

eight hexagons (green-blue).

       

        

        Line 1:Cube,  net and solid .

 Line 2: Truncated octahedron , net and solid