First of all, the total length of the conductor is (the total length of two cuboids plus four heights), that is, (7+5)*4+3*4=60cm.

A cube has 12 sides. So the length of each side is 60 divided by 12=5.

The area of a square is 5*5=25.

A cube has six faces, so the total area is 25*6= 150 square centimeter. That is, 0.015m2.