Question

Three equal cubes of l= 2cm are placed adjacent to each other in a row find tsa of new cuboit ​

Answer 1

Let the side of the cube be ‘x’ units

Total surface of cuboid = 6x2 sq units

Sum of surface ares of three cubes = 3(6x2)= 18x2

Since three equal cubes are placed adjacently, length of the cube will be 3x units

Breadth = x units and height = x units

Total surface area of the cuboid = 2(lb + bh + hl) sq units

Ratio of total surface area of new cuboid to that of the surface area of the three cubes

Hence the ratio is 7:9

Answer 2

Length of each side of cube = 2cm
Length of the cuboid = 2×3 = 6 cm
Breadth = Height = 2 cm
( breadth and height are of same values )
Therefore , Total surface area
= 2(ab+bc+ac)
= 2 ( 6×2 + 2×2 + 6×2 )
= 2 ( 12+4+12)
= 2× 28
= 56 sq. cm