In geometry

Geometry

Geometry arose as the field of knowledge dealing with spatial relationships. Geometry was one of the two fields of pre-modern mathematics, the other being the study of numbers ....

, a decagram is a 10-sided star polygon.

There is one regular decagram star polygon, {10/3}, containing the vertices of a regular decagon, but connected by every third point.

Star figures

There are two regular decagram star figures: {10/2} and {10/4}, connected by every second and every fourth point respectively.

{10/2} or 2{5} is a compound of 2 pentagon Pentagon In geometry, a pentagon is any five-sided polygon. A pentagon may be simple or self-intersecting. The sum of the internal angles in a simple pentagon is 540°. A pentagram is an example of a self-intersecting pentagon.- Regular pentagons :In a regular pentagon, all sides are equal in length and... s.

{10/4} or 2{5/2} is a compound of 2 pentagram Pentagram A pentagram is the shape of a five-pointed star drawn with five straight strokes... s.

Other decagrams

An isotoxal decagram has two types of vertices at alternating radii, for example, this tripled-wrapped figure. This only has D₅ symmetry.