1. The problem statement, all variables and given/known data Show that the maximum possible area for a rectangle inscribed in a circle is 2r^2 where r is the radius of the circle. 2. Relevant equations Pre-calc !! NO TRIG !! Doesn't matter if it's easier, it's supposed to be solved with algebra. 3. The attempt at a solution I have no clue what to do next or if those steps were even correct. Hmm I just noticed that it's not correct. Whatever, I'm still stuck. Idk how to approach this problem.