The moment of a couple is found by multiplying the magnitude of force by the perpendicular distance between the lines of action of the two forces. The direction is determined by inspection.  You will need to determine the perpendicular distance using the known locations of the two points, the direction of the force, geometry and trigonometry as we have done before.

$M = F \cdot d_\perp$

$M = (\var{F}\,  \var{units[1]} ) (\var{abs(siground(moment/F,4))}\,  \var{units[0]} ) = \var{siground(abs(answer),4)}$  Counterclockwise

Alternately, you get the same result by finding the moment of one force about a point on the line of action of the other one.  

So, for example, take the moment of the force at $A$ about point $B$ using Verignon's Theorem. The signs in the equation below are determined by the direction of the component moments, using the sign convention that counterclockwise moments are positive.  The sign of the resulting moment indicates its direction and it should agree with your expectations from inspection of the diagram.

$M = \pm F_x d_y \pm F_y d_x$

$M = \pm\, ( \var{d(Force[0] )} \, \var{units[1]} ) ( \var{d(r[1])} \, \var{units[0]}  ) \pm\, ( \var{d(Force[1] )} \, \var{units[1]} ) ( \var{d(r[0])} \, \var{units[0]}  )$

$M = \var{siground(answer,4)}$

$M = \var{siground(abs(answer),4)}$ Counterclockwise