Question

The total surface area of a cube is $864m^2$. Find the edge length of the cube.

• A. 11 m
• B. 12 m
• C. 13 m
• D. 14 m

Answer 1

The correct option is B 12 m

Total surface area of a cube is given by $6a^2$ (where a is the edge length of the cube)
Hence, $864m^2=6a^2$
$\Rightarrow a^2=144m^2$
$\Rightarrow a=12m$