I attached the drawing.
The force of magnitude F acts along the edge of the triangular plate. Determine the moment of F about point O.
The Attempt at a Solution
What I did was I just picked the top left point of the triangle and labeled that (0,h) which give me my r vector 0i+hj. After that I really don't know how to proceed except to find the angle by doing inverse tangent of h/b, but I just keep getting variable after variable. What other way is there to do this?