1. The problem statement, all variables and given/known data Let ABC be a triangle, and suppose that AB is the largest side. Prove that the perpendicular from C to the line AB crosses at some point D with A*D*B. 2. Relevant equations 3. The attempt at a solution I know that since AB is the largest side, that angle ACB is the largest angle. I also know that CD < CB and CD < CA because a perpendicular is the shortest distance from a point to a line. I think what I want to say is something like: If we have A*B*D, then we would have CB < CD, which is a contradiction. Is this the right line of thinking, or am I going about this the wrong way?