Question

The lateral surface area of a cube is 784sq.cm .Find the lenght of its side.​

Answer 1

$\huge\mathfrak{ \green{solution}}$

Given:

◆ The lateral surface area of the cube is

784cm^2

To find :

◆ Length of its side .

As we know that ,

✧ Lateral surface area of the cube is

$\huge \boxed{ \purple{\bold{ 4 \: {a}^{2} }}}$

$\leadsto \: 4 {a}^{2} = 784 \\ \\ \leadsto \: {a}^{2} = \frac{784}{4} \\ \\ \leadsto \: {a}^{2} = \cancel \frac{784}{4} 196 \\ \\ \leadsto \: a = \sqrt{196} \\ \\ \leadsto \: a = 14$

Hence the length of its side is :

$\huge\boxed{ \red{\bold{14 \: cm}}}$

Answer 2

Given :------ CSA of cube = 784cm²

To Find = Side of cube ..

we know That, A cube with side a , its lateral surface area is = $\large\red{\boxed{\sf Area(A)=</strong><strong>4 {a}^{2</strong><strong>}}}$

So,

$4 {a}^{2} = 784 \\ \\ {a}^{2} = \frac{ \cancel784}{\cancel4} = 196 \\ \\ {a}^{2} = {14}^{2} \\ \\ a = 14$

So, Side of cube is = $\bold{\boxed{\huge{\boxed{\orange{\small{\boxed{\huge{\red{\bold{\:</strong><strong>1</strong><strong>4</strong><strong>c</strong><strong>m</strong><strong>}}}}}}}}}}$

$\color {red}\large\bold\star\underline\mathcal{Extra\:Brainly\:Knowledge:-}$

$\implies \: Tsa \: of \: cube = 6 {a}^{2} \\ \\ \implies \: Volume \: of \: cube = {a}^{3} \\ \\ \implies \: diagonal \: of \: cube = \sqrt{3} a$