Answer:
Scale Factor = 2
Step-by-step explanation:
ABC is your original triangle and A'B'C' is the dilation. You know these are similar triangles so only one side has to be used to find the scale factor. AB has a length of 3 and A'B' has a length of 6 so you know the side lengths of A'B'C' are going to be 2 times the size of triangle ABC side lengths. This gives you a scale factor of 2.