Question

the perimeter of one face of a cube is 20 cm find the total area of the 6 faces and the volume of the cube

Answer 1

P of one face of cube = 4×side
20 = 4 × side

side = 20/4 = 5 cm

Surface area of cube = 6 × side × side = 6 × 5 × 5 = 150 cm sq.

Volume of cube = side × side × side = 5 × 5 × 5 = 125 cubic cm

Answer 2

Let one side of the cube be - 'a'

In a cube all sides are equal.

Given perimeter=20cm

It means
$4a = 20cm \\ \\ a = \frac{20}{4} cm \\ \\ a = 5cm$

Now total area of a cube = Area of one side × 6

$= 6 {a}^{2} \\ \\ = 6 \times {5}^{2} \\ \\ = 150 {cm}^{2}$

And Volume =
${a}^{3} \\ \\ = {5}^{3} \\ \\ = 125 {cm}^{3}$