Recently, I had lab. In the lab we took different objects and measured their strain. One object had a varying cross section. The data for strain was recorded. Right now, i'm trying to make a stress strain graph, but the problem is my equation for stress. I don't know how i can take my moment of intertia about the z-axis. I looked all over the web. In addition, I tried contacting my TA but no success for the pass 3 days. If you can help, I would appretiate it. Edit: I have the equations for the slopes. The problem lies with my moment of inertia.