2a. Cuboctahedron 8/3 6/4 from truncation of cube 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 cuboctahedron to the centre of the square(red) is EA×0.71

These two distances are equal, thus EA = EP×0.71 (Alternative calculation: E_A =Ö2 E_P/2 = 0.71)

Construction

EP is divided in two equal parts.

. The six squares (red) are applied on the original squares

The eight corners (yellow) are cut off, resulting in eight triangles (green-blue)

Line 1: Cube net and solid. Line 2: Cuboctahedron net and solid .