ABSTRACT
Departures and latitudes are X and Y components of a survey line superimposed onto a horizontal plane with a directional reference system. Triangulation is a type of horizontal control comprised of triangles. The simplest triangulation is intersection where a baseline distance is measured, a theodolite erected at the two ends of the baseline, and horizontal angles measured to a third point from these stations. Any method of adjustment is assumed to balance only random errors accumulated in the survey. A distance and direction can be computed between any two points in a survey when their coordinates or departure and latitude between them are known, whether direct measurements between the points are made or not. Areas of rectangles, trapezoids, and parallelograms are required in many land surveying problems. The state plane coordinate system is a system for using plane coordinates over large areas without accumulating errors due to earth's curvature and meridian convergence.
