Answer:
Second number line(from top to bottom).
Step-by-step explanation:
We are given the following inequality:

It is solved similarly to an equality, so:


Multiplying by -1, the signal changes from < to >. So



Thus the correct answer is given by the second number line.
Triangles have 3 vertices. The total is 21 vertices. 21 / 3 = 7. He drew 7 triangles.