Two forces are acting on an object at the same point. Determine the angle between the two forces. F1 = 〈-1,4〉F2 = 〈3,-1〉54°122°234°304°

I think the answer is 122, key is to make a body diagram with the origin as the same point. see the forces are opposing ? F1 is in 2nd quadrant, F2 is in 3rd quadrant. Inverse tangent gives the angle between the force and x-axis.

the angle between is:
180 - arctan(4) + arctan(1/3) = 122