Question

A unit cube is cut into two equal halves by a plane section parallel to one of its faces. The total surface area of both the halves is

• A. $6$ sq cm
• B. $7$ sq cm
• C. $8$ sq cm
• D. $9$ sq cm

Answer 1

Answer: (C)

$8$ sq cm

Initially, $l=1$, $b=1$, $h=1$
After cutting the cube into two halves, the new cuboid will have length has $1$ cm, breadth has $1$ cm and height has $\frac{1}{2}$ cm
Surface area of one cuboid $=2(lb+bh+hl)$
$=2(1\times 1+1\times \frac{1}{2}+1\times \frac{1}{2})$
$=2\left(2\right)$
$=4$ cm${}^2$
Area of both the cuboids combined $=2\times 4=8c{m}^2$