Question

Find the edge of the cube whose surface area is 432 sq. metres.

Answer 1

Given,

The surface area of a cube is 432 sq. metres.

To find,

Length of edge of this cube

Main solution :

We know ,

Surface area of a cube is given by = 6 × a^2

Here, a stands for side . Side and edge are the same thing.

Now, forming an equation using the given data in the question:-

$6{a}^{2}=432$

Now, we have one unknown variable and one equation in the same variable.

Solving for a :

${a}^{2}=\frac{432}{6}$

${a}^{2}=72$

$a=\sqrt{72}$

$a=6\sqrt{2}$

a is equal to plus minus 6√2 . Since, length of side can't be in negative , we consider the positive value of a.

a(edge) = 6√2 (Answer )