- Sphere (Wikipedia)
A sphere (from Greek σφαῖρα, sphaîra) is a geometrical object that is a three-dimensional analogue to a two-dimensional circle. Formally, a sphere is the set of points that are all at the same distance r from a given point in three-dimensional space. That given point is the center of the sphere, and r is the sphere’s radius. The earliest known mentions of spheres appear in the work of the ancient Greek mathematicians.
- Guyana (Wikipedia)
Guyana (/ɡaɪˈɑːnə/ or /ɡaɪˈænə/ ghy-A(H)N-ə), officially the Co-operative Republic of Guyana, is a country on the northern coast of South America, part of the historic mainland British West Indies. Guyana is an indigenous word which means “Land of Many Waters”. Georgetown is the capital of Guyana and is also the country’s largest city. Guyana is bordered by the Atlantic Ocean to the north, Brazil to the south and southwest, Venezuela to the west, and Suriname to the east. With a land area of 214,969 km2 (83,000 sq mi), Guyana is the third-smallest sovereign state by area in mainland South America after Uruguay and Suriname, and is the second-least populous sovereign state in South America after Suriname; it is also one of the least densely populated countries on Earth. It has a wide variety of natural habitats and very high biodiversity. The country also hosts a part of the Amazon rainforest, the largest tropical rainforest in the world.
