Question

2 cubes each of volume 64 cm3 are joined end to end. Find the surface area of the resulting cuboid.

Answer 1

Answer:

Volume = 64 cm3

a^3 = 64 cm3

a = 4 cm [Side]

After joining ,

New length = 4+4 = 8 cm

New breadth = 4cm

New height = 4cm

Surface Area = 2(lb + bh +hl)

= 2 ( 32 + 16+16)

= 126 cm2

Answer 2

Answer:

In the figure above two cubes are joined end to end such that a cuboid is formed.Volume of cube = 64 cm3

We know that,

Side of cube =  

=  

= 4 cm

Side of cube = 4 cm

Now these two cubes when joined, we can see from the figure that, their lengths are added and breadth and height remains the same.

Length of new cuboid = 8 cm

Height of new cuboid = 4 cm

Width of new cuboid = 4 cm

We know that:

Surface Area = 2(lb + lh + bh)

Surface Area = 2(8 x 4 + 8 x 4 + 4 x 4)

= 2 x 80

= 160 cm2