Finding the point where the line of action intersect with r

[werson tan]

Homework Statement

I'm having problem of finding the point where the line of action intersect with CD , hot to do it ?
Fx = -500cos60 - 250(4/5)
Fy = 300 + 500sin60 + 250(3/5)
FR = 991N

Homework Equations

The Attempt at a Solution

 

[haruspex]

What can you say about moments?

 

[werson tan]

What can you say about moments?

moment = rF r = perpendicular distance from the force... Is there any shortcut to do this question ? or just keep on trial and error until get the correct ans ??

 

[haruspex]

moment = rF r = perpendicular distance from the force... Is there any shortcut to do this question ? or just keep on trial and error until get the correct ans ??

No, I mean what is the relationship between the moments of the forces and torque in the diagram about C and the moment of the equivalent force?