Definition of Decagon at Dictionary.comDecagon: Definition and Shape - Video and Lesson Transcript What is a 10-sided shape called?
A decagon is a ten-sided polygon or 10-gon.The interior angles of a simple decagon are 1440.
A regular decagon has all sides of equal length and each internal angle is equal to 144.The Schlfli symbol is 10 and can be constructed as a truncated pentagon, t5, a decregularagon alternating two types of edges.
Where d is the distance between parallel sides or the diameter of the decagon's inscribed circle is an alternative formula.By simple math.
A regular decagon can be constructed using compass and straightedge, or by an edge-bisection of a regular pentagon.[5]
The golden ratio is the length ratio of two edges of a golden triangle.
We can get the properties of a regular decagonal star by tiling by golden triangles.
The golden ratio is the dividing of a line segment by the exterior division of the determining construction element.
The decagon has Dih10 symmetry.There are 3 subgroup dihedral symmetries.
The decagon has a larger number of symmetries because the lines of reflections can either pass through the edges or the vertices.These are labeled by a letter and group order.There is no symmetry labeled a1 in the regular form.The dihedral symmetries are divided by whether they pass through the diagonal or edges.The central gyration orders of cyclic symmetries are labeled as g in the middle column.
The subgroup symmetry allows for more freedom for irregular forms.The g10 subgroup has no degrees of freedom but can be seen as directed edges.
d10 is an isogonal decagon constructed by five mirrors which can alternate long and short edges, and p10 has equal edge lengths but different internal angles.The two forms have half the symmetry of the regular decagon.