Interior angles of a regular 18 gon (octdecagon) are 160o.
A regular octdecagon (18 sided geometric figure) was internal angles of 160 degrees.
The interior angle of an octdecagon, an 18 sided regular polygon, is 160o.
10 - Decagon 11 - Hendecagon 12 - Dodecagon 13 - Triskaidecagon or Tridecagon 14 - Tetraidecagon or Tetradecagon 15 - Pendecagon 16 - Hexdecagon 17 - Heptdecagon 18 - Octdecagon 19 - Enneadecagon 20 - Icosagon Occasionally, Mathmaticians will refer to these as n-gons. So a 17 Sided Polygon could just be called a 17-gon.
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