Answer:
6 inches
Explanation:
For an edge length of s, the six square faces of the cube add to an area of ...
cube area = 6s²
Filling in the given information and solving for s, we get
216 = 6s²
36 = s² . . . . . divide by 6
√36 = s = 6 . . . . take the square root
The edge length is 6 inches.