نجمة تساعية
نجمة تساعية Enneagram | |
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المضلعات النجمية |
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في الهندسة، النجمة التساعية enneagram nonagram, nonangle, or enneagon، هي مضلع ثماني الرؤوس. [1]
The word 'enneagram' combines the numeral prefix ennea- with the Greek suffix -gram. The gram suffix derives from γραμμῆς (grammēs) meaning a line.[2]
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النجمة التساعية الاعتيادية
A regular enneagram is a 9-sided star polygon. It is constructed using the same points as the regular enneagon, but the points are connected in fixed steps. Two forms of regular enneagram exist:
- One form connects every second point and is represented by the Schläfli symbol {9/2}.
- The other form connects every fourth point and is represented by the Schläfli symbol {9/4}.
There is also a star figure, {9/3} or 3{3}, made from the regular enneagon points but connected as a compound of three equilateral triangles.[3][4] (If the triangles are alternately interlaced, this results in a Brunnian link.) This star figure is sometimes known as the star of Goliath, after {6/2} or 2{3}, the star of David.[5]
Compound | Regular star | Regular compound |
Regular star |
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Complete graph K9 |
{9/2} |
{9/3} or 3{3} |
{9/4} |
نجمات تساعية أخرى
The final stellation of the icosahedron has 2-isogonal enneagram faces. It is a 9/4 wound star polyhedron, but the vertices are not equally spaced. |
The Fourth Way teachings and the Enneagram of Personality use an irregular enneagram consisting of an equilateral triangle and an irregular hexagram based on 142857. |
The Bahá'í nine-pointed star |
A 9/3 enneagram |
The nine-pointed star or enneagram can also symbolize the nine gifts or fruits of the Holy Spirit.[6]
في الثقافة العامة
- The heavy metal band Slipknot previously used the {9/3} star figure enneagram[7] and currently uses the {9/4} polygon as a symbol. The prior figure can be seen on the cover of All Hope Is Gone.
انظر أيضا
- Nonagon (enneagon)
- List of regular star polygons
For the use of the enneagram in other contexts, see:
- نجمة تساعية (توضيح)
- Enneagram of Personality
- Fourth Way Enneagram
- Arica School
- Fruit of the Holy Spirit
- Baha'i Houses of Worship
المصادر
- ^ "Between a square rock and a hard pentagon: Fractional polygons". 28 September 2017.
- ^ γραμμή, Henry George Liddell, Robert Scott, A Greek-English Lexicon, on Perseus.
- ^ Grünbaum, B. and G. C. Shephard; Tilings and Patterns, New York: W. H. Freeman & Co., (1987), ISBN 0-7167-1193-1.
- ^ Grünbaum, B.; Polyhedra with Hollow Faces, Proc of NATO-ASI Conference on Polytopes ... etc. (Toronto 1993), ed T. Bisztriczky et al., Kluwer Academic (1994) pp. 43-70.
- ^ Weisstein, Eric W. "Nonagram". mathworld.wolfram.com.
- ^ Our Christian Symbols by Friedrich Rest (1954), ISBN 0-8298-0099-9, page 13.
- ^ "slipknot". eBay.