More advanced FBD problems-need some tips

[caddyguy109]

Anybody?

 

[caddyguy109]

Okay, my last plead... ...

Can anyone help me figure out #2:
2) http://www.ihostphotos.com/show.php?id=182816

This was said here:
"at least it's a 90 degree angle! and frictionless ...
try taking Moments around the place where the two F_N intersect
did you sum F_x and F_z first?"

but I just can't, for whatever reason, get it going. Where the heck do I take the sum of moments about? And how do I then express the angle (theta) corresponding to equilibrium as a function of M, W, and L?

This is the LAST question for a while, I swear