1. The problem statement, all variables and given/known data Problem is in image uploaded 2. Relevant equations n/a 3. The attempt at a solution x = u, y = v and z = 1 - u - v ∂r/∂u × ∂r/∂v = i + j + k F dot N = u^2 + 3v^2 ∫∫(u^2 + 3v^2 )dudv My problem is i'm not sure what I should take as the limits? Should I flip around the order of integration (dvdu) and have v go from 0 to 1-u and have u go from 0 to 1?