Moment of inertia of a "music triangle" 1. The problem statement, all variables and given/known data Find the moment of inertia about an axis thru the centre of mass, perpendicular to the plane of an equilateral triangle consisting of identical rods of length 'l' and mass 'm' connected at their ends. 2. Relevant equations Classical mechanics, maybe centre of inertia theorem (or whatever its called) 3. The attempt at a solution not sure, is it possible to "approximate" the three rods as three point masses?