1. The problem statement, all variables and given/known data Find the angle theta that maximizes the area of an isosceles triangle whose legs have length l. The angle is the top angle if the left and right sides are l coming to a point with the bottom leg horizontal. 2. Relevant equations 3. The attempt at a solution I broke the triangle up into two halves to use right angle trig and eventually got the area to equal A=l^2 * sin(theta/2)*cos(theta/2). When I took the derivative though I realized that I would have too many variables. I think theres a way to solve for l in terms of theta or theta in terms of l but I'm not sure how to do it can anyone point me in the right direction.