The last step that Wei did to complete his construction was to mark the point D on the line CD¯¯¯¯¯¯¯¯ such that CD¯¯¯¯¯¯¯¯ is congruent to AB¯¯¯¯¯¯¯¯.
To determine the last step that Wei did to complete his construction, I would need more information or the image mentioned in the question to understand the specific construction steps. Can you provide additional details or a description of the steps involved in Wei's construction?
