A enneadecagon or 19-gon is a shape with 19 sides and 19 corners. It is also known as an enneakaidecagon or a nonadecagon.
All sides of a regular enneadecagon are the same length. Each corner is ≈161.052°. All corners added together equal 6840°.
The radius of the circumcircle of the regular enneadecagon with side length t is
(angle in degrees). The area, where t is the edge length, is
- ↑ Borges, Samantha; Morgan, Matthew (2012), Children's Miscellany: Useless Information That's Essential to Know, Chronicle Books, p. 110, ISBN 9781452119731.
- ↑ McKinney, Sueanne; Hinton, KaaVonia (2010), Mathematics in the K-8 Classroom and Library, ABC-CLIO, p. 67, ISBN 9781586835224.