pentagon
A pentagon is a 5-sided planar polygon.
Regular pentagons are of particular interest for geometers. On a regular pentagon, the inner angles are equal to . All ten diagonals have the same length. If is the length of a side and is the length of a diagonal, then
that is, the ratio between a diagonal and a side is the Golden Number.
A regular pentagon (along with its diagonals) can also be obtained as the projection of a regular pentahedron in four dimensional space onto a plane determined by two opposite edges. This is analogous to the way a square with its diagonals can be obtained as the projection of a tetrahedrononto a plane determined by two opposite edges.
Title | pentagon |
---|---|
Canonical name | Pentagon |
Date of creation | 2013-03-22 12:10:19 |
Last modified on | 2013-03-22 12:10:19 |
Owner | rspuzio (6075) |
Last modified by | rspuzio (6075) |
Numerical id | 8 |
Author | rspuzio (6075) |
Entry type | Definition |
Classification | msc 51-00 |
Related topic | Triangle |
Related topic | Polygon |
Related topic | Hexagon |
Related topic | RegularDecagonInscribedInCircle |