Thanks to all for the nice feedback!
Do they pentagonal faces turn?
No, the only turning axes are located at the five square faces. These are the equivalents of the five axes on Fracture-10.
can this be done?
You can get two triangles to show up on one square face (as you've drawn on the yellow face or purple face), but not on two adjacent square faces. The triangular piece you've drawn on the yellow face could not share an edge with the triangular piece on the purple face since the two pieces would need to occupy the same space.