Coordinates of the triangle ABC:
A(-2,2).
B(2,1)
C(-1,-2).
And the coordinates of the dilated triangle A'B'C':
A'(-4,4)
B'(4,2)
C'(-2,-4).
We can clearly see that each x and y-coordinate of triangle ABC is being multiplied by 2 to get the coordinates of triangle A'B'C'.
Therefore, triangle ABC is being dilated by a scale factor of 2.