Question

If 4 cubes of side 2 cm are joined together side by side to form a cuboid, then the total surface area of cuboid formed is.

• A. $72{\text{cm}}^2$
• B. $82{\text{cm}}^2$
• C. $92{\text{cm}}^2$
• D. $102{\text{cm}}^2$

Answer 1

The correct option is A $72{\text{cm}}^2$

Given : Edge of cube = 2 cm
When four cubes are joined together their height and breadth will remain same but their length becomes 4 time.
Length of new cuboid formed $=2\times 4=8\text{cm}$
Breadth of new cuboid formed = 2 cm
Height of new cuboid formed = 2 cm
Total surface area of cuboid formed
= 2(lb + bh +hl)
$=2(8\times 2+2\times 2+2\times 8)$
$=2(16+4+16)$
$=72{\text{cm}}^2$