Evaluate the line integral QF . dr by evaluating the surface integral in Stokes' Theorem with an appropriate choice of C S. Assume that C has a counterclockwise orientation when viewed from above. F = (x2 - y2,z2 -x2, y2 -z2) C is the boundary of the square |x| s 27, |y| s 27 in the plane z = 0. Rewrite the given line integral as an area integral over the appropriate region of the xy-plane. OF . dr = dA C R Evaluate the integral. OF . dr = ( Type an exact answer.) C