Question

At what angle must the two forces 50N and 120N be acting so as to be balanced by a force of 130N

Answer 1

@eSpeX : I think the angle desired is between 50 and 120 Newton. In your diagram, that's 90 already ( so it's not a variable). I think the diagram was constructed wrongly, maybe?

Answer 2

The diagram should be something like this, I think. @eSpeX