Question

There are
triangles.

Answer 1

There are altogether 10 triangles.

Answer 2

Answer:

13

Step-by-step explanation:

We can count the triangles systematically by side length:

i.e. 1-length triangles: 9

    2-length triangles: 3

     3-length triangles: 1

So total is 9+3+1 = 13.