Answer:
6cm
Explanation:
if C is the mid point of AB, then segment AC and BC would be of equal size . And if D is the midpoint of AC then segment AD and DC would be of same size as well. SO, IF AD=3cm THEN DC=3cm. AND AC=AD+DC , AC=3+3=6.
SO, If AC and BC are of same size that means BC is also =6cm
SORRY IF THIS IS RLY CONFUSING