1. The problem statement, all variables and given/known data A certain type of concrete has a tensile breaking stress of 3.1 MN/m^2, a compressive breaking stress of 37.7 MN/m^2 and a shear breaking stress of 9.4 MN/m^2. A circular pillar of this concrete has a radius of 0.6 m. What is the maximum load it can support assuming that it is evenly distributed over the top of the pillar? 2. Relevant equations Normal stress, [PLAIN]http://upload.wikimedia.org/math/9/d/4/9d43cb8bbcb702e9d5943de477f099e2.png=F/A [Broken] Shear stress, [PLAIN]http://upload.wikimedia.org/math/d/9/5/d95fd1519e587418ebe3da8fb081701f.png=F/A [Broken] 3. The attempt at a solution I haven't dealt with this sort of problem where the object has more than one type of stress applied to it. I tried finding the maximum load (or force) by adding up all the stresses and multiplying by the area which in this case is πr^2 but this doesn't give me the correct answer. I'm running out of ideas, could Pythagoras' theorem be considered? Please help!