What is a nonagon?

A nonagon or 9-gon is a nine-sided polygon through nine internal angles that sum to 1260°. A nonagon is likewise called one enneagon. In plenty of ways, enneagon is a much more accurate term, since it uses Greek roots for both the prefix (ennea-, meaning nine) and also suffix (-gon, angled).

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Nonagons space rarely used in many geometry texts, however it is an intriguing shape, whether you research a consistent nonagon or an irregular nonagon.


Nonagon shape

To it is in a nonagon or enneagon, the shape must have actually all these properties:

It should be 2 dimensional (planar)It should use just nine line segmentsIt need to close in an area

The nine heat segments are the nonagons" sides, and also they attach to form the nonagons" angles.


Nonagon sides

A nonagon has actually nine right sides of same length. If the sides room all the same length, then you have a constant nonagon. If the sides differ in length, climate you have an irregular nonagon.


If the sides space curved, the is not a nonagon.

Nonagon angles

Every nonagon has actually nine internal angles that sum to 1260°, and the ripe exterior angle of a nonagon sum to 360°.


Every basic nonagon (not complex) have the right to have it"s interior separated into 7 triangles.


You can uncover the amount of inner angles by multiplying 7 × 180°, i m sorry is how you acquire 1260°.

Nonagon diagonals

Because every diagonal has actually 9 inner angles that connect, a nonagon has actually 27 diagonals.


Regular nonagon

A consistent nonagon shape has actually 9 same sides and 9 congruent angles. In a continual nonagon, each internal angle steps 140°.

A consistent nonagon is a subtle and beautiful design:


It is an extremely nearly a circle, yet not quite. The inner angles room each 140°. You have the right to verify this because 1260° ÷ 9 (angles) = 140°.

The central angle is 40° (which you can calculate by separating 360° through 9). This method you have the right to construct a constant nonagon v 7 isosceles triangles v two angle of 70° and also one edge of 40°.

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Irregular nonagon

Irregular nonagons can have political parties of various lengths and interior angles of differing sizes. Yet, even odd shapes prefer these room nonagons:


A polygon through at the very least one interior angle greater than 180° is a concave polygon and constantly created an irregular polygon.