Finding Torque problem!

Hi friends and Sir's ,

I am stumbled upon a problem and unable to solve it , can any one tell me what will be the torque at A and how you did that?

here is my problem :
http://img180.imageshack.us/img180/550/torquexu4.png [Broken]

thanks!!

 

I already told my question that i need to find the torque about point A but i am having problem with the torque 20 nm that how to or resolve that torque about A .
Btw the distance btw 4m line and point a is also 4 m. My semster exams are on 7 may. So please just tell me how to solve it.
Thanksss

btw

 

Can you be little more descriptive this doesn't clears my concept at all! means can you tell me
with easy language that how to solve if torque is given on other point (x,y) and some forces then how to find torque about a point (x1,y1) (means on another coordinate) , thanks again

 

no one else? , thanks in advance!