Question

Find the side of a cube when its total surface area is 486 cm2

Answer 1

surface area =486 cm2
6 X ( side ) 2 = 486 cm2
(side)2=( 486/6)cm2
side=√81 cm
side= 9cm

Answer 2

For a cube all sides are equal.

Volume of a cube = $a^3$

and Surface area of a cube=$6a^2$,

where a = side of the square.

So when we are given surface area we can easily find the side of the cube. Using the side we are going to find volume of the cube.

Since total surface area = 486 sq cm. we can find a using this.

$6a^2 =486:</p><p>a^2 =81</p><p>a =9$

Side = 9 cm.

Hence volume = 9x9x9 = 729 cubic cm.