Based on the information provided, it seems that Lucia constructed two segments \(AB\) and \(CD\) using a straightedge and compass, which typically suggests that these segments are created in a geometric context where they may be equal or have a specific ratio based on a construction.
Given the options regarding the relationship between \(AB\) and \(CD\):
- \(AB = CD\)
- \(AB = 2CD\)
- \(AB = \frac{1}{2}CD\)
Without more specific information about the construction or the relationship intended in this problem, it is reasonable to conclude that:
- If Lucia constructed \(AB\) and \(CD\) to be equal, then \(AB = CD\).
- If she was asked to create two segments such that one is twice the length of the other, then \(AB = 2CD\).
- Conversely, if one segment is half the length of the other, then \(AB = \frac{1}{2}CD\).
If Lucia simply copied one segment using a straightedge and compass, the most likely answer is that \(AB = CD\), because copying directly indicates equality.
Thus, if asked what can be said about \(AB\) and \(CD\) under the assumption that \(AB\) was constructed to be a copy of \(CD\), the answer would be:
AB = CD.