Question

If the lateral surface area of the cube is 100cm${}^2$, then its side will be ____________cm.

• A. 25cm
• B. 20cm
• C. 5cm
• D. 10cm

Answer 1

The correct option is C 5cm

The lateral surface area of a cube with side 'a' is 4a${}^2$.
So, 4a${}^2$ = 100
a${}^2$ = $\frac{100}{4}$ = 25
$\therefore$ a = $\sqrt{2}5$ = 5cm