1. The problem statement, all variables and given/known data im trying to find the center of mass of two identical strong square pizza boxes of dimension one inch deep by 18 inches wide one is placed on top of the other with the edge of the top box in line with the center of mass of the bottom box , 2. Relevant equations n/a , the boxes have uniform distribution of mass . 3. The attempt at a solution using symmetry considerations , the c.o.m. of the system is at about line 3/4 of the length from the leading edge of the top box . the purpose of this is to try and solve the "book stacking problem" i want to solve for the first two first.