How many triangles in the picture?

Question

Sorry if this has already been asked before. Is there any formula for such questions?

EDIT:

I have numbered the smallest triangles in the picture and marked the pentagon as x. Then I listed all the possibilities. Could you please check if I have missed anything?

1, 2, 3, 4, 5, 6, 7, 8, 23, 34, 45, 56, 67, 78, 345, 567, 2x8, 2x6, 234x8, 2x876, 1x465, 1x4, 1x6, 8x4

Answer 1

Thanks to help from Raskolnikov and Wood the answer is 24 triangles.

Answer 2

No formula. I simply counted them and got 22.

There are 9 individual parts, out of which 8 are triangles themselves.

• Triangles made by 1 part - 8
• Made by 2 parts - 5
• Made by 3 parts - 6
• Made by 4 parts - 0
• Made by 5 parts - 3

Total 22.