



 
Hi Bryan, The key to solving this is Pythagoras Theorem. It amazes me how often the key to solving a practical problem is Pythagoras Theorem. Suppose the diameter of the round stock is $d$ inches. In the diagram above the triangle $ABC$ is a right triangle and Pythagoras Theorem states that for a right triangle the square of the length of the hypotenuse (the long side) is the sum of the squares of the lengths of the other two sides. Thus \[d^2 = 3.25^2 + 3.25^ 2 = 10.5625 + 10.5625 = 21.125 \mbox{ square inches}\] and thus \[d = \sqrt{21.125} = 4.596 \mbox{ inches}\] I hope this helps,  


Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences. 