To find the length of \( AB \), we need to analyze triangle \( DBE \) and use the properties of congruent triangles.
In triangle \( DBE \):
- \( DB = 12 \) units
- \( BE = 7 \) units
- \( DE = 14 \) units
First, we can apply the triangle inequality to see if triangle \( DBE \) is valid:
- \( DB + BE = 12 + 7 = 19 > DE \) (14) - Valid
- \( DB + DE = 12 + 14 = 26 > BE \) (7) - Valid
- \( BE + DE = 7 + 14 = 21 > DB \) (12) - Valid
Since triangle \( DBE \) is valid, we can also assume that triangle \( ABC \) might be congruent to triangle \( DBE \) based on congruent segments and angles.
If angles opposite to the sides are congruent in both triangles (a common assumption in congruent triangles), then:
- If \( DE \) corresponds to \( AB \),
- And \( DE = 14 \) units,
Thus, from congruence, we can conclude that: \[ AB = DE = 14 \text{ units.} \]
Therefore, the answer is \( 14 \) units.