In order to calculate the area of a square, which make part of a cube. You use the following formula:
A = a²
where a is the length of the side of the square and A is the area.
Then, you have to calculate the value of a. To do that, you use the information abou the volume of the cube and you use the following formula:
V = a³ solve for a by applying cubic root both sides
³√V = a replace V = 216 in³
a = ³√V
a = ³√(216 in³)
a = 6 in
Then, the length of the side of the square is 6 inches.
Next, you replace the value of a in the formula for the calculation of the area:
A = a²
A = (6 in)²
A = 36 in²
Hence, the are of the square is 36 in²