Stat Indet Truss

So, here is what we get when we `add' (superpose) the statically determinate and applied reaction cases:

It's kind of wild in that the top member forces go to zero. In reality, those top members would carry load ... certainly their self weights, and perhaps the load from the deck (if, say, part of a bridge.)

Also, in reality, there will be some allowance for (some) movement in (some of) the joints.