The provided nonagon ABCDEFGHI has sides AB, BC, CD, DE, EF, FG, GH, HI, and IA and angles ∠A, ∠B, ∠C, ∠D, ∠E, ∠F, ∠G, ∠H, and ∠I.

You are watching: Interior angle of a regular nonagon

The blue line segments AC and BD are its diagonals.

There are full of 27 diagonals in a nonagon as displayed below:

**Angles that a nonagon:**

A nonagon consists of 9 angles. The sum of angles of a nonagon is 1260°.

A nonagon has actually 9 exterior angles. The sum of angles of the exterior angles of a nonagon is 360°.

**Non-examples**

The complying with shapes space not nonagons. Let us see why?

There are an ext than 9 sides in this figure. So, that is not a nonagon. | |

There space 8 sides in this figure. So, it is no a nonagon. |

**Regular nonagon**

A nonagon in which all sides room equal and all angles are equal is a constant nonagon.

Each edge of a continual nonagon is of 140°.

**Irregular nonagon**

A nonagon in which all sides are not equal and all angles room not equal. The measure of its angles room different yet total amount of all its interior angles is always 1260°.

A nonagon is likewise called enneagon, i beg your pardon is derived from a Greek word called enneagonon, which means nine corners. The first use of words nonagon dates ago to the early 17th century, and has a Latin prefix (nona) and a Greek suffix (gon), making the a polygon v nine sides and also nine angles. |