Question

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

Answer 1

Given, volume of each cube is 64 cm³

⇒s³=64

⇒s=∛64

⇒s=4 cm.

When two cubes are joined , 

the length of the resulting cuboid(l) = side + side = 4+4 = 8 cm

its breadth(b) = side = 4cm

And its height(h) = side = 4cm

Total surface area of a cuboid = 2(lb+bh+hl)

⇒TSA=2[(8)(4)+(4)(4)+(4)(8)]

⇒TSA=2(32+16+32)

⇒TSA = 2(80)

⇒TSA = 160 cm²

∴ The surface area of the resulting cuboid is 160 cm

Answer 2

$\huge \underline \mathsf \red {AnsWer:-}$

Given:

• The Volume (V) of each cube is = 64 cm³.

This implies that a³ = 64 cm³

Therefore, a = 4 cm

Now,

The side of the cube = a = 4 cm

Also, the length and breadth of the resulting cuboid will be 4 cm each. While its height will be 8 cm.

So, the surface area of the cuboid = 2(lb + bh + lh)

= 2(8×4 + 4×4 + 4×8) cm²

= 2(32 + 16 + 32) cm²

= (2 × 80) cm²

= 160 cm²

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