This is the problem which comes from trying to be too smart. You should not use Greek prefices if you do not understand them. There is no such thing as a tridecagon: a 13-gon is a triskaidecagon whereas a 30-gon is a triacontagon. Stick to simple forms through which you can communicate rather than try and be pretentious!
The interior angles sum to 1980 degrees.
A tridecagon has 13 angles
It is 180 :)
A triangle has no diagonals
A tridecagon is a 13 sided polygon. Also called a triskaidecagon.
triskaidecagon or a tridecagon. triskaidecagon or a tridecagon.
A 13 sided polygon is called a Tridecagon also a Triskaidecagon.
A link to a picture of a regular tridecagon (also known as a triskaidecagon), a thirteen-sided polygon, can be found below this answer.
Triskaidecagon or Tridecagon
A tridecagon has 13 sides and can be divided into triangles by drawing diagonals from one vertex to all other non-adjacent vertices. This results in exactly 11 triangles, as each vertex connects to 10 other vertices, but each triangle shares sides with others. Therefore, the number of triangles that can be formed within a tridecagon is 11.
tridecagon
tridecagon i thinkk??