How many triangles in a undecagon?

There are 9 triangles in an 11 sided shape

Nine, as a n-gon can be cut in n-2 triangles.

3 Isosceles triangle, Equilateral triangle, and Scalene triangle.

What type of triangle?

27 triangles. There are 16 one-cell triangles, 7 four-cell triangles, 3 nine-cell triangles, and 1 sixteen-cell triangle.