We can see that both triangles are identical to each other, except that the second is bigger than the first. We can also see that the second triangle's side lengths are one unit more than the first. Let's take the top line as an example: Figure 1 is 3 units long while Figure 2 is 4 units long. To find the scale factor, you divide the shorter length by the longer length and in this problem, you would get 3/4, or 0.75% (which is A).
Hope this helped!
