Thus, each point in space has a fixed position. To specify the position of a point, | its perpendicular distance from the YZ plane must be determined (this gives the x value of point P) | | its perpendicular distance from the XZ plane must be determined (this gives the y value of point P) | | its perpendicular distance from the XY plane must be determined (this gives the z value of point P) | Point p is written P (x, y, z). Thus, for example, if point P is | 3 units from the origin (zero point) on the x axis, | | 2 units on the y axis and | | 1 unit on the z axis: | it is written P(3, 2, 1). | | |