Answer:
Area of a rectangle is Width * Length
Apply this to each area the question asks for
AreaTop = 8cm * 4cm = 32
AreaBottom = the same, 32
AreaFront = 2cm * 4cm = 8
AreaBack = the same, 8
AreaLeftSide = 2cm * 8cm = 16
AreaRightSide = the same, 16
TotalSurfaceArea = 16 + 16 + 8 + 8 + 32 + 32 = 112