How do you calculate the moment of a force about a point?

[United]

Homework Statement

http://imgur.com/7DDxqJp
Find the moment generated about point O by the force, F1.

Homework Equations

Moment = Perpendicular Force * distance

The Attempt at a Solution

I tried plugging in that, because sqrt(3^2+4^2)=5, that my result would be either 6cos(30)*5 or 6sin(30)*5, but both of those answers are wrong

 

[TSny]

You need to find the component of the force that is perpendicular to the rod. So, you will need to find the angle between the force and the rod. It might help if you first find the angle that the force makes with respect to the horizontal direction (x direction).