Contents

### Heptagon Definition, Properties, Types, Formula, Example

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TOPICS Algebra Applied Mathematics Calculus and Analysis Discrete Mathematics Foundations of Mathematics Geometry History and Terminology Number Theory Probability and Statistics Recreational Mathematics Topology Alphabetical Index New in MathWorld

Geometry Plane Geometry Polygons

Download Wolfram Notebook A heptagon is a seven-sided polygon, It is also sometimes called a septagon, though this usage mixes a Latin prefix sept- (derived from septua-, meaning “seven”) with the Greek suffix -gon (from gonia, meaning “angle”), and is therefore not recommended.

## Does a heptagon have 8 sides?

Properties of Heptagon –

It has seven sides, seven angles, and seven vertices. Sum of interior angles of a heptagon is 900°.

$⦣1 + ⦣2+ ⦣3+ ⦣4+ ⦣5+ ⦣6+ ⦣7 = 900°$

It has 14 diagonals.

#### What is 9 sided shape called?

Angles of a Nonagon: – A nonagon consists of 9 angles. 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°. Non-examples The following shapes are not nonagons. Let us see why?

There are more than 9 sides in this figure. So, it is not a nonagon. | |

There are 8 sides in this figure. So, it is not a nonagon. |

Regular nonagon A nonagon in which all sides are equal and all angles are equal is a regular nonagon. Each angle of a regular nonagon is of 140°. Irregular nonagon A nonagon in which all sides are not equal and all angles are not equal. The measure of its angles are different but total sum of all its interior angles is always 1260°. Fun facts about nonagons 1. A nonagon is also called enneagon, which is derived from a Greek word called enneagonon, which means nine corners.2. The first use of the word nonagon dates back to the early 17th century, and has a Latin prefix (nona) and a Greek suffix (gon), making it a polygon with nine sides and nine angles.

## What is a 10 sided shape called?

Decagon Definition – In geometry, a polygon having ten sides or a ten-sided polygon is called a decagon or ten-gon. It also has ten vertices and ten angles. In the above image, there are 10 sides: AB, BC, CD, DE, EF, FG, GH, HI, IJ, and AJ. There are 10 angles. Decagon interior angles: $\angle\text $, $\angle\text $, $\angle\text $, $\angle\text $, $\angle\text $,$\angle\text $, $\angle\text $, $\angle\text $, $\angle\text $, and $\angle\text $ There are 10 vertices: A, B, C, D, E, F, G, H, I, and J.

### What is a 12 sided polygon?

A dodecagon is a 12-sided polygon.

#### What is a 11 sided shape called?

TOPICS Algebra Applied Mathematics Calculus and Analysis Discrete Mathematics Foundations of Mathematics Geometry History and Terminology Number Theory Probability and Statistics Recreational Mathematics Topology Alphabetical Index New in MathWorld

Geometry Plane Geometry Polygons

Download Wolfram Notebook A hendecagon is an 11-sided polygon, also variously known as an undecagon or unidecagon. The term “hendecagon” is preferable to the other two since it uses the Greek prefix and suffix instead of mixing a Roman prefix and Greek suffix.

### What is a 3d shape with 8 sides called?

Irregular octahedra – The following polyhedra are combinatorially equivalent to the regular polyhedron. They all have six vertices, eight triangular faces, and twelve edges that correspond one-for-one with the features of a regular octahedron.

- Triangular : Two faces are equilateral, lie on parallel planes, and have a common axis of symmetry. The other six triangles are isosceles.
- Tetragonal, in which at least one of the equatorial quadrilaterals lies on a plane. The regular octahedron is a special case in which all three quadrilaterals are planar squares.
- , a non-convex polyhedron that cannot be partitioned into tetrahedra without introducing new vertices.
- , a non-convex self-crossing

More generally, an octahedron can be any polyhedron with eight faces. The regular octahedron has 6 vertices and 12 edges, the minimum for an octahedron; irregular octahedra may have as many as 12 vertices and 18 edges. There are 257 topologically distinct convex octahedra, excluding mirror images.

- : Two faces are parallel regular hexagons; six squares link corresponding pairs of hexagon edges.
- Heptagonal : One face is a heptagon (usually regular), and the remaining seven faces are triangles (usually isosceles). It is not possible for all triangular faces to be equilateral.
- : The four faces from the tetrahedron are truncated to become regular hexagons, and there are four more equilateral triangle faces where each tetrahedron vertex was truncated.
- : The eight faces are congruent,
- Octagonal : degenerate in Euclidean space, but can be realized spherically.

#### What polygon has 35 diagonals?

A polygon has 10 sides is known as decagon. ∴ Decagon has 35 diagonals.

### What is a 20 sided shape called?

2nd century B.C.–4th century A.D. A number of polyhedral dice made in various materials have survived from the Hellenistic and Roman periods, usually from ancient Egypt when known. Several are in the Egyptian or Greek and Roman collections at the Museum.

The icosahedron – 20-sided polyhedron – is frequent. Most often each face of the die is inscribed with a number in Greek and/or Latin up to the number of faces on the polyhedron. Nothing specific about the use of these polyhedra is preserved, so theories are built on clues provided by some variant examples.

One unusual example uses Greek words, a few of which resemble those associated with throws of the astragals (knucklebones), and this has led to suggestions they were used for games. Another remarkable example discovered in Dakhleh Oasis in Egypt in the 1980s records an Egyptian god’s name in Demotic (the Egyptian script of these late periods) on each face.

- Divination – seeking advice about the unknown from the supernatural – seems to be the most likely purpose for the Dakhleh die: the polyhedron might have been thrown in order to determine a god who might assist the practitioner.
- Indeed, even the dice with simple letters might relate to divination: a Greek oracle book composed in in the 2nd or 3rd century A.D.

refers to throwing lots to obtain a number that would, through certain algorithms, lead to ready-prepared oracle questions and responses.

## Is there a 2 sided shape?

From Wikipedia, the free encyclopedia

Regular digon | |
---|---|

On a circle, a digon is a tessellation with two antipodal points, and two 180° arc edges. | |

Type | Regular polygon |

Edges and vertices | 2 |

Schläfli symbol | |

Coxeter–Dynkin diagrams | |

Symmetry group | D 2,, (*2•) |

Dual polygon | Self-dual |

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.

A regular digon has both angles equal and both sides equal and is represented by Schläfli symbol, It may be constructed on a sphere as a pair of 180 degree arcs connecting antipodal points, when it forms a lune, The digon is the simplest abstract polytope of rank 2. A truncated digon, t is a square,,

An alternated digon, h is a monogon,,

## What is a billion sided shape?

A gigagon is a two-dimensional polygon with one billion sides.

### What are 13 sided shapes called?

A 13-sided polygon, sometimes also called the triskaidecagon.

#### What is a 200 sided shape?

What is the name of a polygon with?

# | Name of the Polygon + Geometric Drawing |
---|---|

100 sides | hectogon |

200 sides | dihectogon |

300 sides | trihectogon |

400 sides | tetrahectogon |

#### What are 14 sided shapes called?

A tetradecahedron is a 14-sided polyhedron, sometimes called a tetrakaidecahedron.

#### What is a 15 sided shape called?

An pentadecagon is a 15 sided polygon with interior angles that add to 2340 degrees.

## What is a 1 million sided shape called?

In geometry, a polygon with 1 million sides is called a megagon.

### What is a 17 sided polygon called?

The regular polygon of 17 sides is called the heptadecagon, or sometimes the heptakaidecagon. Gauss proved in 1796 (when he was 19 years old) that the heptadecagon is constructible with a compass and straightedge, Gauss’s proof appears in his monumental work Disquisitiones Arithmeticae., where the are distinct primes of the form

(1) |

known as Fermat primes, Constructions for the regular triangle ( ), square ( ), pentagon ( ), hexagon ( ), etc., had been given by Euclid, but constructions based on the Fermat primes =17″> were unknown to the ancients. The first explicit construction of a heptadecagon was given by Erchinger in about 1800. The trigonometric functions and are both algebraic numbers of degree 8 given respectively by The heptadecagon with unit edge lengths has inradius and circumradius given by both of which can be expressed in terms of finite root extractions. They can also be expressed as the largest roots of the algebraic equations

(6) | |

(7) |

The area of the regular heptadecagon is given by

(8) |

where can be expressed as the largest root of

(9) |

The following elegant construction for the heptadecagon (Yates 1949, Coxeter 1969, Stewart 1977, Wells 1991) was first given by Richmond (1893).1. Given an arbitrary point, draw a circle centered on and a diameter drawn through,2. Call the right end of the diameter dividing the circle into a semicircle,3. Construct the diameter perpendicular to the original diameter by finding the perpendicular bisector,4. Construct a quarter of the way up,5. Join and find so that is a quarter of,6. Find so that is,7. Construct the semicircle with diameter,8. This semicircle cuts at,9. Draw a semicircle with center and radius,10. This cuts the line segment at,11. Construct a line perpendicular to through,12. This line meets the original semicircle at,13. You now have points and of a heptadecagon.14. Use and to get the remaining 15 points of the heptadecagon around the original circle by constructing,,,,,,,,,,,,,,,, and,15. Connect the adjacent points for to 17, forming the heptadecagon. This construction, when suitably streamlined, has simplicity 53. The construction of Smith (1920) has a greater simplicity of 58. Another construction due to Tietze (1965) and reproduced in Hall (1970) has a simplicity of 50. and simplicity 45. The construction problem has now been automated to some extent (Bishop 1978).

## What shape has 7 unequal sides?

Irregular Heptagon – A heptagon is irregular if it has 7 unequal sides and angles. Irregular heptagons can all look very different.

### What is a 7 and 9 sided shape called?

Here, a 3-sided polygon is a triangle, 4 sided polygon is a quadrilateral, 5-sided polygon is a pentagon, 6-sided polygon is a hexagon, 7-sided polygon is heptagon, 8-sided polygon is octagon, 9-sided polygon is called a nonagon and a 10-sided polygon is the decagon.

#### How many faces does a septagon have?

In geometry, a heptagon or septagon is a seven-sided polygon or 7-gon.