If the area of the triangle formed by the points  $(2a,b), (a+b, 2b+a)$ and  $(2b,2a)$is 2 sq. units then the area of the triangle  whose vertices are $\left(a+b,a-b\right),\left(3b-a,b+3a\right)$ and  $\left(3a-b,3b-a\right)$ will be