**1. The problem statement, all variables and given/known data**

**2. Relevant equations**

**3. The attempt at a solution**

I don’t think the given problem requires me to find an expression of potential energy as a function of the equal side lengths. Also, I am not sure how would I set up the integral even if I want to find the expression for potential energy. There is probably some trick to this question but I am honestly clueless about it.

Any help is appreciated. Thanks!

http://ift.tt/1bKRRsA