Vector is of length 2 cm and is 60 above the x-axis in the first quadrant. Vector is of length 2 cm and 60 below the x-axis in the fourth quadrant. The sum + is a vector of magnitude -
Vector A has a magnitude of 2 cm at an angle of 60° above the x-axis. Vector B has the same magnitude of 2 cm but at 60° below the x-axis. Their sum A + B will be a vector along the positive x-axis with a magnitude of 2√3 ≈ 3.46 cm.