Four forces in the x−y plane act on an irregularly shaped object that is free to rotate about the z axis. Note that the z axis, which passes through the origin, is perpendicular to the x−y plane and points out of the screen.

Force F⃗ 1, with a magnitude of F1=1.36N, is applied at a point on the y axis a distance r1=2.63m from the origin at an angle α=29.6∘ below the horizontal, as shown.
Force F⃗ 2, with a magnitude of F2=3.72N, is applied at a point that is a distance r2=4.14m from the origin and is perpendicular to a line connecting its point of application to the origin.
Force F⃗ 3, with a magnitude of F3=3.72N, is applied at a point on the x axis a distance r3=2.63m from the origin at an angle of β=18.7∘ with the vertical, as shown.
Force F⃗ 4, with a magnitude of F4=1.36N, is applied at the origin.

What is the magnitude, in newton-meters, of the net torque about the z
axis?