How to extract a bearing (azimuth) for a polyline.
A Line_Bearing attribute field can be added to a polyline attribute table by
using the Add Geometry Attributes tool. The bearing is the direction from
the start to end nodes of the polyline. Directions are geographic 0=North,
90=East, 180= South, etc. This same tool can return the starting, ending
and midpoints coordinates of a line, centroid coordinates of polygons, and
several other geometric properties.
