Answer:
256
Step-by-step explanation:
Here we have two square and one invisible part (where those square are touching)
The 1st square has dimension:
4x4x5
The 2nd hs dimension: 8x4x5
The formula of surface are for square is
S=2B+M
For first
S1=2x4x5+2x4x5+2x4x4=40+40+32=112
For 2nd
S2=2x5x4+2x5x8+2x4x8=40+80+64=184
The invisible part is are 4x5=20 which we added in s1 and also in s2, so we have to remove.
The all area is:
s1+s2-2x20=112+184-40=256