- Uruguay (Wikipedia)
Uruguay (/ˈjʊərəɡwaɪ/ YOOR-ə-gwy, Spanish: [uɾuˈɣwaj]), officially the Oriental Republic of Uruguay (Spanish: República Oriental del Uruguay), is a country in South America. It shares borders with Argentina to its west and southwest and Brazil to its north and northeast, while bordering the Río de la Plata to the south and the Atlantic Ocean to the southeast. It is part of the Southern Cone region of South America. Uruguay covers an area of approximately 176,215 square kilometres (68,037 sq mi) and has a population of around 3.4 million, of whom nearly 2 million live in the metropolitan area of its capital and largest city, Montevideo.
- Star polygon (Wikipedia)
In geometry, a star polygon is a type of non-convex polygon. Regular star polygons have been studied in depth; while star polygons in general appear not to have been formally defined, certain notable ones can arise through truncation operations on regular simple or star polygons.