Answer:
Segment Addition Postulate
Explanation:
The whole line segment would be AB. The midpoint of the line segment would be D. If we add AD (the first portion of the line segment), and DB (the second portion of the line segment), then we get AB (A-D-B)
Representation:
(AD) (DB)
|--------------------------|---------------------------|
A D B
|------------------------------------------------------|
(line segment AB)