Question

Two cubes each of edge 2 cm are joined face to face. Find the total surface area of the cuboid thus formed.

• A. 40 $c{m}^2$
• B. 30 $c{m}^2$
• C. 20 $c{m}^2$
• D. 60 $c{m}^2$

Answer 1

The correct option is A 40 $c{m}^2$


Look at the above figure. Cube has six faces, when two equal cubes are placed together, two side faces are not visible.

We are left with 12 - 2 = 10 square faces.

We know that,
surface area of square face $=(\text{edge}{)}^2$.
$\therefore$ Surface area of cuboid formed
$=10\times (\text{edge}{)}^2$
$=10\times (2{)}^2$
= 40 $c{m}^2$