It was observed that the efficiency of many geometric algorithms for orthogonal polygons does not really depend on the fact that their sides meet at right angles, but rather on the fact that their sides are naturally split into two alternating sets (of vertical and horizontal segments).
Notices indicated that the efficiency of several geometric algorithms for orthogonal polygons is not really dependent on the perpendicularity of their sides, but rather on the inherent property of their sides being split into two alternating groups (vertical and horizontal segments) that facilitates their operation.