The surface is the portion of the hemi -sphere x^2 +y^2 +z^2 =25

above z= 4

z= sqrt(25-x^2 -y^2)

N = -dz/dx i -dz/dy j + K

N = x/sqrt(25-x^2) i + y /sqrt(25-y^2) j + k

The region of integration is the circle x^2 + y^2 = 9

(using z=4)

See the attachment for the calculation of the line integral using both Stokes Theorem and the definition of line integral