Static Equilibrium is when there is no acceleration in any direction. There can, however, be movement. It just has to be at a constant velocity. Newton's second law is the basis of Static Equilibrium
When forces are at an angle, you need to make sure to break them down into two components. In the X direction and the Y direction. Doing this, you can calculate the magnitude of the force by: SQRT((x1-x2)^2+(y1-y2)^2)