To determine the measure of \( \overline{AC} \), we first need to understand how Nozomi constructed \( \overline{AC} \). It was mentioned that point \( B \) is used as an endpoint for the copy of \( \overline{AB} \), meaning that \( \overline{AC} \) extends from point \( A \) to point \( C \) with \( C \) being the new point created by this operation.
Since \( \overline{AB} \) has a measure of 22.3 millimeters, and \( \overline{AC} \) is formed by extending this segment continuously using \( B \) as a new endpoint, we can deduce the length of \( \overline{AC} \).
Assuming \( \overline{AC} \) is formed by placing another segment equal to \( \overline{AB} \) after point \( B \), the total length would be:
\[ AC = AB + BC \]
Here, since \( BC \) is also a copy of \( \overline{AB} \), then:
\[ BC = 22.3 \text{ millimeters} \]
Thus, the total length would be:
\[ AC = 22.3 + 22.3 = 44.6 \text{ millimeters} \]
Therefore, the measure of \( \overline{AC} \) is 44.6 millimeters.
The correct response is:
- The measure of \( \overline{AC} \) is 44.6 millimeters.