Answer:
1350 mm²
Step-by-step explanation:
The area of each square face is the square of the edge length:
... face area = (15 mm)² = 225 mm²
There are 6 square faces on a cube, to the total surface area is 6 times that of one face:
... cube area = 6 × face area = 6×225 mm² = 1350 mm²
