The treasure is at vertex z of a parallelogram. the three other vertices of the parallelogram are located in the following ways: vertex w is 2 meters east and 3 meters north of the flagpole; vertex x is 5 meters east and 7 meters north of the flagpole; and vertex y is 10 meters east and 5 meters south of the flagpole. what would be a convenient location for the flagpole?