By tridecagon, I suppose you are referring to a 13 sided shape. In any shape, you could draw however many triangles you wanted to. If you are after triangles formed by a line from the corners of the shape to the centre, a tridecagon (after the first few shapes, mathematicians usually just use the term n-gon so your 13 sided shape would be called a 13-gon), would contain 13 triangles formed in this way.
A tridecagon is a 13 sided polygon. Also called a triskaidecagon.
Tridecagon
tridecagon
henagon, digon, triangle, quadrilateral, pentagon, hexagon, heptagon, octagon, nonagon, decagon, hendecagon, dodecagon, tridecagon, tetradecagon, pentadecagon, hexadecagon, heptadecagon, octadecagon, nonadecagon, icosagon
tridecagon (or triskaidecagon)
A triangle has no diagonals
A tridecagon has 13 angles
A tridecagon is a 13 sided polygon. Also called a triskaidecagon.
triskaidecagon or a tridecagon. triskaidecagon or a tridecagon.
3 triangle, trigon 12 dodecagon, duodecagon 13 triskaidecagon, tridecagon 14 tetrakaidecagon, tetradecagon 15 pentadecagon
A Monster from Another Universe! You are invited to consider the meaning of the word "triangle". Possibly you're thinking of a triskaidecagon, or tridecagon, which I found in Wikipedia searching "polygon 13 sides." Why bother searching when there are people like me to do it for you?
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
Tridecagon
Tridecagon
Tridecagon