Final answer:
Segment AM is equal to 6 units because point M is the midpoint of segment AE, and by definition of midpoint, AM is half the length of AE.
Step-by-step explanation:
Given that segment AM is congruent to segment ME and the length of segment AE is 12, we need to find the length of segment AM.
By definition of midpoint, point M is the midpoint of segment AE, so AM is half the length of AE.
Therefore, AM = 12/2 = 6.
This can be justified using the definition of midpoint and the addition and subtraction properties.