Octadecagon Octadecagon An octadecagon (or octakaidecagon) or 18-gon is an eighteen-sided polygon. A "regular octadecagon" has a Schläfli symbol {18} and can be constructed as a quasiregular truncated enneagon, t{9}, which alternates two types of edges. As 18 = 2 × 3, a regular octadecagon cannot be constructed using a compass and straightedge. However, it is constructible using neusis, or an angle trisection with a tomahawk. The following approximate construction is very similar to that of the enneagon, as an octadecagon can be constructed as a truncated enneagon. It is also feasible with exclusive use of compass and straightedge. The "regular
Hampton Sides Hampton Sides (Wade) Hampton Sides (born 1962) is an American historian, author and journalist. He is the author of "Americana," "Hellhound on His Trail," "Ghost Soldiers," "Blood and Thunder," and other bestselling works of narrative history and literary non-fiction. Sides is editor-at-large for "Outside" magazine and has written for such periodicals as "National Geographic", "The New Yorker", "Esquire", "Men's Journal", and "The Washington Post". His magazine work, collected in numerous published anthologies, has been twice nominated for National Magazine Awards for feature writing. A native of Memphis, Sides attended PDS Memphis and Memphis University School, and graduated from Yale with