Enneadecagon

From Freepedia

An enneadecagon is a polygon with 19 sides and angles. It is also known as an enneakaidecagon. The internal angles of a regular enneadecagon each measure approximately 161.052 degrees, and the area with side length of a is given by

<math>A = \frac{19}{4}a^2 \cot \frac{\pi}{19} \simeq 28.4652 a^2.</math>

External links

Enneadecagon at MathWorld
Enneakaidecagon at MathWorld

Polygons
Triangle \| Quadrilateral \| Pentagon \| Hexagon \| Heptagon (Septagon) \| Octagon \| Enneagon (Nonagon) \| Decagon \| Hendecagon \| Dodecagon \| Triskaidecagon \| Pentadecagon \| Heptadecagon \| Enneadecagon \| Icosagon \| Tricontagon \| Pentacontagon \| Hectagon \| Chiliagon \| Myriagon