posted by wolfpak .
A body is pivoted at a Point O. Three forces act on it in the directions shown on the figure. FA = 11 N at point A, 8.0 m from O. FB = 15 N at point B, 4.0 m from O. FC = 20 N at point C, 3.0 m from O. What is the net torque about point O?
You have to also have the direction of the force as measured from the line OA, or OB, or OC.
torque= force*distance*cosANGLE between them.