Answer:
a) 1728

b) 512

c) 1000

Explanation:
(I think your question is ...a little mixed up as a square has same length for all of its respective sides. So I will attempt to do them a little differently as I believe the question must have had three different sub questions)
a)

"s" here represents the respective length for the sides.
The answer for if a side was 12 centimeters, then the volume would be

Which would give us a volume of 1728

b)

"s" here represents the respective length for the sides.
The answer for if a side was 8 centimeters, then the volume would be

Which would give us a volume of 512

c)

"s" here represents the respective length for the sides.
The answer for if a side was 10 centimeters, then the volume would be

Which would give us a volume of 1000
