[SOLVED] Optimization: Rectangle Inscribed in Triangle 1. The problem statement, all variables and given/known data Please see http://www.jstor.org/pss/2686484 [Broken] link. The problem I have is pretty much exactly the same as that dealt with in this excerpt. (focus on the bit with the heading "What is the biggest rectangle you can put inside a triangle") 2. Relevant equations Shown in the link above. 3. The attempt at a solution I basically want someone to please explain why we need not use a derivative. As you can see, the last sentence is chopped off and leaves me hanging.