I have sheets (some thing similar to roofing sheets) with bends inclined at 30 and160 degrees. How to stack them alternatively in assembly?

I have tried using mate constraint. I am able to select one sheet surface but the second one can not be selected.
I want to align one sheet over the other with out gap. (Since they are of different inclination, they won’t sit in each other when stacked)

SolidworksAssemblies