Polygonals are a series of sides that can generate a closed or open figure. So, they are a sequence of segments drawn on the reference surface.
Polygonals are generally numbered counterclockwise.
Normally, polygonals haven’t got more than ten sides to not increase the errors; the length of each side must not be greater than 250 - 300 meters and less than 50 - 70 meters.
Each vertex angle of the polygonal is calculated with Bessel’s rule while the extent of each side is obtained from the arithmetic mean between the reading-in and reading-out.
There are various types of polygonals:
- closed polygonals: the first point of the polygonal coincides with the last;
- open polygonals: the first point of the polygonal doesn’t coincide with the last;
- non-oriented polygonals: they are primarily used for the relief of land to calculate the area, because it isn’t necessary to direct the polygonal. Solving a polygonal means to compensate the measure of angles and sides and finally to find the total coordinates of all vertex.