Question

side of cube is 4cm. find the surface area of two cubes when they are joined face to face

Answer 1

When the two cubes are joined :

A cuboid of sides:

Length = 8cm

Width = 4cm

Height = 4cm

Is formed.

The surface area is thus :

(Length × height × 2) + (Length × width × 2) + ( Width × height × 2)

Substituting the values :

(8 × 4 × 2) + (8 × 4 × 2) + (4 × 4 × 2) =

(64) + (64) + (32) = 160 cm²

Answer 2

Solution :-

When two cubes are joined face to face then, 

The length of the cuboid so formed = 4 + 4 = 8 cm

Breadth of the cuboid = 4 cm

Height of the cuboid = 4 cm

Total surface area of the cuboid = 2*(L*B + B*H + H*L)

⇒ 2*(8*4 + 4*4 + 4*8)

⇒ 2*(32 + 16 + 32)

⇒ 2*80

= 160 sq m

Answer