1. The problem statement, all variables and given/known data 2. Relevant equations 3. The attempt at a solution With this problem and in general, I am having difficulties knowing what should be the cubic and what shouldn't be from visual inspection, so in this case I can't tell why I_x is 1/12ba^3, as opposed to 1/12ab^3. How can I tell from looking at this which one is right? Also, the same goes for I_y, is it just the opposite with the b cubed? The solution is also saying Iz = Ix...what?? When it says buckling in the xy plane or xz plane, I am wondering, does that mean the column bulges out normal to the plane, or does it bulge out in the same direction as the plane? Does being braced in a plane imply that its fixed, or does it mean its pinned? Honestly, im wondering why its not Ix = 1/12aL^3...it looks like L is the height and a is the base with regards to the x-axis. A similar idea with problem 10.25. I don't understand why K is 1 in the xz-plane, but 2 in the yz-plane for the effective length. If what I'm thinking is right about how buckling in a plane is in the direction of the plane where the buckling occurs, not normal to it, then for the yz-plane the bar going through the middle impedes the ability to buckle in the y direction, so I guess that end is fixed, but for K=2 that means one end is fixed and one end is free to move, and I don't see which end is free to move here.