1. The Irregular Polygon canvases and Protractor series further extended the concept of the shaped canvas. 2. The bastion consists of an irregular polygon , adapted to the terrain constructed of masonry. 3. The areas of irregular polygons can be calculated using the " Surveyor's formula ". 4. The town, an irregular polygon generally oriented from northeast to southwest, is bordered by Mansfield to the northwest. 5. The bastion-type fortification, is based in an irregular polygon , adapted to the cliff and coastal shoreline. 6. When that's done, you have a set of irregular polygons -one for each closed contour'loop '. 7. These later developed into more elaborate designs, in the " Irregular Polygon " series ( 67 ), for example. 8. The larger is called del Olmo, an ample, irregular polygon , where the weekly market and the annual fair are held. 9. The scheduled area is however contiguous with that of the " irregular polygon " surrounding Whilsa Pund that received similar protection in 1998. 10. An irregular Polygon is not destroyed at birth, but allowed to develop to see if the irregularity can be cured or reduced.