Answer:
0.64m squared
Explanation:
Surface area is the area of the sides added together
I am going to assume that the bottom is a square
0.4 multiplied by 0.6 is 0.24
0.24 halved is 0.12
0.12 multiplied by 4 is 0.48
0.4 multiplied by 0.4 is 0.16
0.48 plus 0.16 is 0.64