Question

Total surface area of a cube is 5400 sq.cm. Find the surface area of all vertical faces of the cube.

Answer 1

Let the edge of the cube be $lcm$.
Total surface area of the cube $=5400c{m}^2$
$\therefore 6l^2=5400$
$\Rightarrow l^2=\frac{5400}{6}=900$
$\Rightarrow l=\sqrt{900}=30cm$
$\therefore$ Surface area of all vertical faces of the cube
$=4l^2$
$=4\times (30cm{)}^2$
$=4\times 900c{m}^2$
$=3600c{m}^2$
Thus, the surface area of all vertical faces of the cube is $3600c{m}^2$.