The 4 have the same number.
Also, it is strange that they look like persons doing different things.
No, you can't count the rhombus or the squares in there. No bisecting lines. The red one has the most with 9 triangles while all the others have only 5.
But if it allowed you to add lines, any number of triangles could be in there. Since you could still bisect other triangles to make more. :o