Polygon with holes - Wikipedia

Pick's theorem - Wikipedia

Toroidal Polyhedron

File:Polygon types.svg - Wikipedia

merge - Union on polygons with holes using JSTS? - Geographic

Polygon with holes - Wikipedia

File:Regular polygon truncation 9 2.svg - Wikipedia

Converting a polygon with holes into multiple simple polygons

File:Complex polygon 3-4-3.png - Wikipedia

upload.wikimedia.org/wikipedia/commons/thumb/0/03/

Anthropomorphic polygon - Wikipedia