Answer:
12 units
Explanation:
A-------6--------B-------?--------C
Midpoint is center that divides the line segment into two equal halves.
∴ AB = BC
If line AB measures 6 units in length, then, line BC will measure 6 units in length.
AB = BC = 6 units
AC = AB + BC
AC = 6 units + 6 units
AC = 12 units
OR
We can say If B is the midpoint of AC, then AC is twice as long as AB.
AC = 2AB
AC = 2 × 6 units
AC = 12 units
Therefore, the length of line AC is 12 units.