Answer:
12 in.
Step-by-step explanation:
Surface area of cube: 6a^2
Surface area= 864 inches
864= 6a^2
/6 /6
144= a^2
[tex]\sqrt{144\\}[/tex]= [tex]\sqrt{a^2\\}[/tex]
a= 12 or -12
A side can't be a negative number, so the answer is 12 in.
