An air-traffic controller observes two aircraft on his radar screen. The first is at altitude 800 m,

Question:

An air-traffic controller observes two aircraft on his radar screen. The first is at altitude 800 m, horizontal distance 19.2 km and 25.0° south of west. The second aircraft is at altitude 1 100 m, horizontal distance 17.6 km and 20.0° south of west. What is the distance between the two aircraft? (Place the x axis west, the y axis south, and the z axis vertical.)