This is how to build the Cuboctahedron, and its Dual, the Rhombic Dodecahedron. A Dual is where each face of one polyhedron matches to a vertex of the other.  This model uses the GreenLines. To build like in these instructions, it takes extra Yellow struts such as can be found in a Creator 3 kit. 

You can find more models that use the GreenLines here.