A parallelepiped of the dimensions you give is not a cube. A cube has 6 square faces.
The area of your right parallelepiped will be twice the sum of the following
(2 ft)*(6 ft), (2 ft)*(8 ft), and (6 ft)*(8 ft).
Each face of a given size has a matching one of the same size on the opposite side of the object.
total area = 2(12 ft2 + 16 ft2 + 48 ft2) = 2(76 ft2) = 152 ft2.
The area of your right parallelepiped will be twice the sum of the following
(2 ft)*(6 ft), (2 ft)*(8 ft), and (6 ft)*(8 ft).
Each face of a given size has a matching one of the same size on the opposite side of the object.
total area = 2(12 ft2 + 16 ft2 + 48 ft2) = 2(76 ft2) = 152 ft2.
