How many sides does a polygon with 9 diagonals have?

diagonals, as each vertex has diagonals to all other vertices except itself and the two adjacent vertices, or n − 3 diagonals, and each diagonal is shared by two vertices….Polygons.

How regular hexagon has 9 diagonals?

$ \Rightarrow {D_n} = \dfrac{{n\left( {n – 3} \right)}}{2}$ , where ${D_n}$ is a number of diagonals. For regular hexagon values of n=6. Therefore, in a regular hexagon the number of diagonals is 9. So, the correct option is (b).

What does a 9 sided polygon equal to?

nonagon
In geometry, a nonagon (/ˈnɒnəɡɒn/) or enneagon (/ˈɛniəɡɒn/) is a nine-sided polygon or 9-gon.

What is a polygon with 9 diagonals?

For n = 6, n-polygon is called hexagon and it has 9 diagonals. Therefore, the number of diagonals in a polygon hexagon is 9.

What is the name of a 9 sided shape?

Nonagons
It has nine straight sides that meet at nine corners. The word nonagon comes from the Latin word “nona”, meaning nine, and “gon”, meaning sides. So it literally means “nine sided shape”. Nonagons are also called enneagon, which comes from the Greek word “enneagonon”, which means “nine corners”.

What is the sum of the exterior angles of a polygon with 9 sides?

360°
Angles of a nonagon: The sum of angles of a nonagon is 1260°. A nonagon has 9 exterior angles. The sum of angles of the exterior angles of a nonagon is 360°.

How many diagonals are there in a polygon of 10 sides?

35 diagonals
How many diagonals of a regular decagon (a 10 sided polygon) are not parallel to any of the sides (AMC12)? A decagon has (10 2) – 10 = 35 diagonals. Each pair of opposing sides has three diagonals which are parallel to them, so 5*3 = 15 of the diagonals are parallel to a side.