25 relations: Ancient Greek, Angle trisection, Area, Charles Sanders Peirce, Circumscribed circle, Compass-and-straightedge construction, Constructible polygon, Cyclic group, Dihedral group, Directed graph, Geometry, Harold Scott MacDonald Coxeter, Hypercube, Incircle and excircles of a triangle, Internal and external angles, John Horton Conway, Petrie polygon, Polygon, Polygram (geometry), Regular polygon, Schläfli symbol, Star polygon, Truncation (geometry), Vertex configuration, Zonogon.

## Ancient Greek

The Ancient Greek language includes the forms of Greek used in ancient Greece and the ancient world from around the 9th century BC to the 6th century AD.

New!!: Enneacontagon and Ancient Greek ·

## Angle trisection

Angle trisection is a classical problem of compass and straightedge constructions of ancient Greek mathematics.

New!!: Enneacontagon and Angle trisection ·

## Area

Area is the quantity that expresses the extent of a two-dimensional figure or shape, or planar lamina, in the plane.

New!!: Enneacontagon and Area ·

## Charles Sanders Peirce

Charles Sanders Peirce ("purse"; 10 September 1839 – 19 April 1914) was an American philosopher, logician, mathematician, and scientist who is sometimes known as "the father of pragmatism".

New!!: Enneacontagon and Charles Sanders Peirce ·

## Circumscribed circle

In geometry, the circumscribed circle or circumcircle of a polygon is a circle which passes through all the vertices of the polygon.

New!!: Enneacontagon and Circumscribed circle ·

## Compass-and-straightedge construction

Compass-and-straightedge construction, also known as ruler-and-compass construction or classical construction, is the construction of lengths, angles, and other geometric figures using only an idealized ruler and compass.

New!!: Enneacontagon and Compass-and-straightedge construction ·

## Constructible polygon

In mathematics, a constructible polygon is a regular polygon that can be constructed with compass and straightedge.

New!!: Enneacontagon and Constructible polygon ·

## Cyclic group

In algebra, a cyclic group or monogenous group is a group that is generated by a single element.

New!!: Enneacontagon and Cyclic group ·

## Dihedral group

In mathematics, a dihedral group is the group of symmetries of a regular polygon, which includes rotations and reflections.

New!!: Enneacontagon and Dihedral group ·

## Directed graph

In mathematics, and more specifically in graph theory, a directed graph (or digraph) is a graph that is a set of vertices connected by edges, where the edges have a direction associated with them.

New!!: Enneacontagon and Directed graph ·

## Geometry

Geometry (from the γεωμετρία; geo- "earth", -metron "measurement") is a branch of mathematics concerned with questions of shape, size, relative position of figures, and the properties of space.

New!!: Enneacontagon and Geometry ·

## Harold Scott MacDonald Coxeter

Harold Scott MacDonald "Donald" Coxeter, FRS, FRSC, (February 9, 1907 – March 31, 2003) was a British-born Canadian geometer.

New!!: Enneacontagon and Harold Scott MacDonald Coxeter ·

## Hypercube

In geometry, a hypercube is an ''n''-dimensional analogue of a square and a cube.

New!!: Enneacontagon and Hypercube ·

## Incircle and excircles of a triangle

In geometry, the incircle or inscribed circle of a triangle is the largest circle contained in the triangle; it touches (is tangent to) the three sides.

New!!: Enneacontagon and Incircle and excircles of a triangle ·

## Internal and external angles

In geometry, an angle of a polygon is formed by two sides of the polygon that share an endpoint.

New!!: Enneacontagon and Internal and external angles ·

## John Horton Conway

John Horton Conway FRS (born 26 December 1937) is an English mathematician active in the theory of finite groups, knot theory, number theory, combinatorial game theory and coding theory.

New!!: Enneacontagon and John Horton Conway ·

## Petrie polygon

In geometry, a Petrie polygon for a regular polytope of n dimensions is a skew polygon in which every (n – 1) consecutive sides (but no n) belongs to one of the facets.

New!!: Enneacontagon and Petrie polygon ·

## Polygon

In elementary geometry, a polygon is a plane figure that is bounded by a finite chain of straight line segments closing in a loop to form a closed polygonal chain or circuit.

New!!: Enneacontagon and Polygon ·

## Polygram (geometry)

In geometry, a generalized polygon can be called a polygram, and named specifically by its number of sides, so a regular pentagram,, has 5 sides, and the regular hexagram, or 2 has 6 sides divided into two triangles.

New!!: Enneacontagon and Polygram (geometry) ·

## Regular polygon

In Euclidean geometry, a regular polygon is a polygon that is equiangular (all angles are equal in measure) and equilateral (all sides have the same length).

New!!: Enneacontagon and Regular polygon ·

## Schläfli symbol

In geometry, the Schläfli symbol is a notation of the form that defines regular polytopes and tessellations.

New!!: Enneacontagon and Schläfli symbol ·

## Star polygon

In geometry, a star polygon is a type of non-convex polygon.

New!!: Enneacontagon and Star polygon ·

## Truncation (geometry)

In geometry, a truncation is an operation in any dimension that cuts polytope vertices, creating a new facet in place of each vertex.

New!!: Enneacontagon and Truncation (geometry) ·

## Vertex configuration

In geometry, a vertex configuration by Walter Steurer, Sofia Deloudi, (2009) pp.

New!!: Enneacontagon and Vertex configuration ·

## Zonogon

In geometry, a zonogon is a centrally symmetric convex polygon.

New!!: Enneacontagon and Zonogon ·

## Redirects here:

90 symmetry, 90-gon, Enenecontagon, Enneacontagram.