it has 13 sides
If you mean a triskaidecagon then it has 65 diagonals
If you mean a triskaidecagon then it has 13 sides
triskaidecagon or a tridecagon. triskaidecagon or a tridecagon.
triskaidecagon
Triskaidecagon or Tridecagon
triskaidecagon
triskaidecagon
Triskaidecagon
Tridecagon (or triskaidecagon).Check out a list that includes the first 20 at the University of Regina Related Link, below.
there are 27 triangles in a triangle
There are 15 triangles in a 17-agon