# What type of polygon has 21 sides?

## What type of polygon has 21 sides?

An icosikaihenagon is a 21-sided polygon. Most mathematicians and mathematics students would simply write “21-gon” to name it.

## What is the sum of the interior angles of a polygon that has 21 sides?

The interior angle of a regular 21-gon is around 162.86∘ .

**What polygon has 21 diagonals?**

Therefore, a quadrilateral has two diagonals, joining opposite pairs of vertices. For any convex polygon, all the diagonals are inside the polygon, but for re-entrant polygons, some diagonals are outside of the polygon….Polygons.

Sides | Diagonals |
---|---|

21 | 189 |

22 | 209 |

23 | 230 |

24 | 252 |

**How many diagonals are there in a polygon having 21 sides?**

Diagonals of one vertex equals to: 21 (number of vertex) – 1 (itself) – 2 (sides with vertices next to it). So the answer should be: That’s different from 170 obtained above.

### What polygon has 720 sides?

Hexagon

Hence, the type of polygon required is a Hexagon.

### What is the exterior angle of a 21 sided polygon?

If the 21 sided polygon is regular, each exterior angle = 360/21 = 17 and 1/7 degrees and each interior angle = 180 – 17 and 1/7 = 162 and 6/7 degrees, and the sum of the 21 interior angles = 21 * (162.8571429) = 3420º.

**How do you find the interior angle of a polygon with 20 sides?**

Each exterior angle of a regular polygon of 20 sides = 360/20 = 18 deg. Each interior angle of a regular polygon of 20 sides = 180 – 18 = 162 deg. Total sum of the 20 interior angles of the regular polygon = 162*20 = 3240 deg.

**What is 20 polygon called?**

icosagon

In geometry, an icosagon or 20-gon is a twenty-sided polygon.

## What polygon has 170 diagonals?

20-sided

Another way to express the general rule for the total number of diagonals is to think about the number of diagonals that can be drawn from each vertex in a polygon. That is “3” less than the number of sides. Therefore, for a 20-sided polygon, there will be 190 lines and 170 diagonals.

## Do polygons have 8 sides?

In geometry, an octagon (from the Greek ὀκτάγωνον oktágōnon, “eight angles”) is an eight-sided polygon or 8-gon….Octagon.

Regular octagon | |
---|---|

A regular octagon | |

Type | Regular polygon |

Edges and vertices | 8 |

Schläfli symbol | {8}, t{4} |

**Can polygons have 2 sides?**

In geometry, a digon is a polygon with two sides (edges) and two vertices. Its construction is degenerate in a Euclidean plane because either the two sides would coincide or one or both would have to be curved; however, it can be easily visualised in elliptic space.

**What shape has 21 sides?**

What is a shape with 21 sides called? An icosikaihenagon is a 21-sided polygon. Most mathematicians and mathematics students would simply write “21-gon” to name it.

### What are the interior angles of a 20 sided polygon?

The sum of the interior angles of a 20-gon is 3,240°. A 20-gon is a 20-sided regular polygon (all sides and interior angles are equal). What is the sum of the interior angles of a 25 Gon? That’s the same as 2 times 180, which is why Mark took two from the N and THEN multiplied by 180.

### What is the name of polygon with 22 sides?

In geometry, an icosidigon (or icosikaidigon) or 22-gon is a twenty-two-sided polygon. The sum of any icosidigon’s interior angles is 360 degrees. The regular icosidigon is represented by Schläfli symbol {22} and can also be constructed as a truncated hendecagon, t {11}.

**What polygon has 12 sides and 12 vertices?**

The most common polygons are those with a small amount of sides, such as triangles with three sides and squares with four sides. A dodecagon has 12 straight edges in a closed loop along with 12 vertices where the edges meet.