So in my physics class we built cardboard chairs as a project. Part of the assignment is to draw in all of the stresses, and then do calculations to see how much stress exists in all of the structural members. One of my main structural members is a triangle, its peak attaches to the main panel that one would sit on. All of the calculations are easy except this one, because it is the only structural member that is not vertical, and my question is: does it matter this piece isn't vertical? Like would I say (force parallel to member)/area to find stress, or would it just be (force)/area like a vertical piece? I've attached an image to make my question more clear...I'm looking to find the stress on the red member. I didn't include values because arithmetic isn't a problem. Thanks!