Answer: B the side length of XZ is 28
Step-by-step explanation:
to find the scale factor, one of the methods is to divide the side length of one triangle by the same side length of the other triangle.
for example with this problem, the length of XY is 42 while side length AB is 12. 42/12 is 3.5. we know that the side length that corresponds with XZ is 8 so multiply it by 3.5 to get the answer of 28.