How do you know whether a table of values represent a linear relation?

Which statement accurately explains whether a reflection over the x-axis and a 180° rotation would map figure acb onto itself?

To prove that def ~ gfh by the sss similarity theorem using the information provided in the diagram, it would be enough additional information to know that

How many different three-digit numbers can be formed using the digits 1 comma 2 comma 9 comma 6 comma 4 comma 3 comma and 8 without repetition? for example, 664 is not allowed.