In the figure, a radar station detects an airplane approaching directly from the east. At first observation, the airplane is at distance d₁ = 320 m from the station and at angle ₁ = 33 above the horizon. The airplane is tracked through an angular change = 121 in the vertical east-west plane; its distance is then d₂ = 790 m. Find the (a) magnitude and (b) direction of the airplane's displacement during this period. Give the direction as an angle relative to due west, with a positive angle being above the horizon and a negative angle being below the horizon.