Question

Find the length of edge of a cube with following surface area

$1944c{m}^2$ and $2646c{m}^2$

• A. $28cm;21cm$
• B. $17cm;21cm$
• C. $18cm;21cm$
• D. $18cm;20cm$

Answer 1

The correct option is C $18cm;21cm$

Total surface area (TSA) of cube $=6(edge{)}^2$

When TSA is $1944c{m}^2$

$\therefore 6(edge{)}^2=1944$

$\Rightarrow (edge{)}^2=\frac{1944}{6}$

$\Rightarrow edge=\sqrt{324}=18cm$

When TSA is $2646c{m}^2$

$\therefore 6(edge{)}^2=2646$

$\Rightarrow (edge{)}^2=\frac{2646}{6}$

$\Rightarrow \left(edge\right)=\sqrt{441}=21cm$