The Total solution for NCERT class 6-12
By joining three cubes of side 4 cm each, end is end, we get acuboidLength of cuboid = 4 x 3 = 12 cmBreadth = 4 cmand height = 4 cm∴Surface area = 2(lb + bh + hl)= 2[12 x4+4×4 + 4x 12] cm2= 2[48 + 16 + 48] cm2= 2 x 112 = 224 cm2