enneakaidecagonal

Enneakaidecagonal refers to a polygon with nineteen sides. The term is derived from Greek, with "enneakaideka" meaning nineteen and "gonia" meaning corner or angle. Therefore, an enneakaidecagon is a 19-sided polygon.

In Euclidean geometry, an enneakaidecagon can be either regular or irregular. A regular enneakaidecagon has all sides of equal length and all interior angles equal. The measure of each interior angle in a regular enneakaidecagon is (19-2) * 180 / 19 degrees, which simplifies to 17 * 180 / 19, or approximately 170.53 degrees. The sum of the interior angles of any enneakaidecagon, regular or irregular, is (19-2) * 180 degrees, which equals 3060 degrees.

Like all polygons, an enneakaidecagon can be convex or concave. A convex enneakaidecagon has all interior angles less than 180 degrees, while a concave one has at least one interior angle greater than 180 degrees. The concept of an enneakaidecagon is a direct extension of the principles of polygon nomenclature, following the established pattern for naming polygons based on their number of sides.