Vector A→ is 2 cm long and is 60o above the x-axis in the first quadrant. Vector B→ is 2 cm long and is 60o below the x-axis in the fourth quadrant. The sum A→ + B→ is a vector of magnitude

Here the angle between two vectors of equal magnitude is 120. So resultant has the same magnitude as either of the given vectors. Moreover, it is mid-way between the two vectors, i.e., it is along x-axis