Answer:
A. Add the endpoints
C. Divide -12 by 2
Explanation:
To find the midpoint of the vertical line segment with endpoints (0, 0) and (0, -12).
Step 1: Add the endpoints (y-coordinates)
0+-12=-12
Step 2: Divide -12 by 2
-12/2=-6
Therefore, the y-coordinate of the midpoint of a vertical line segment is -6.
Options A and C are correct.