1. The problem statement, all variables and given/known data an isosceles with base=a, height=h. It has uniform density and negligible thickness. 2. Relevant equations determine it's centre of mass by integration,using more than one orientation PHP: 3. The attempt at a solution It is a two-dimensional continuous structure. Let the base,a, lie on the X-axis and the Y-axis be axis of symmetry. Then the COM must lie on the Y-axis. Slice the triangle into strips parallel to the X-axis. Each strip is of width dy, and length l. The mass per strip,dm, is obtained through: mass=density x area, p l dy and the variable of integration is y as it is the axis of symmetry and integration is over 0 and h.