Final answer:
The scale factor for similar triangles is determined by the ratio of the corresponding side lengths.
Step-by-step explanation:
The scale factor for the given similar triangles is determined by the ratio of the corresponding side lengths. In this case, if ΔABC∼ΔDEF, then the scale factor is the ratio of the corresponding side lengths AB:DE, BC:EF, and AC:DF. The scale factor can be represented as a fraction or a ratio, depending on the given information.
For example, if AB:DE = BC:EF = AC:DF = 1:4, then the scale factor is 1/4 or 1:4.