Question

If the perimeter of base of a cube is $14cm$ and its height is $3.5cm$, then its lateral surface area is

• A. $36c{m}^2$
• B. $422c{m}^2$
• C. $49c{m}^2$
• D. $56c{m}^2$

Answer 1

Answer: (C)

$49c{m}^2$

Let $a$ be the length of side of the given cube.

Perimeter of base of the cube will be $4a$

Given perimeter of base $=14$ cm

According to the given condition

$4a=14cm$

$a=\frac{14}{4}=\frac{7}{2}cm$

Lateral surface Area $=4a^{2}c{m}^2$

$=4{\left(\frac{7}{2}\right)}^{2}c{m}^2$

$=4\times \frac{49}{4}c{m}^2$

$=49c{m}^2$