Question

3) Find the radius of a sphere whose Surface area is 314sq.cm (take 2pai =3·14) ​

Answer 1

Answer:

→ 5 cm

Step-by-step explanation:

Given that ,

• Surface Area of sphere is 314 sq. cm

We have to find ,

• Radius of Sphere

Solution :

We know that —

$\: \: \: \: \: \: \: \: \: \: \: \: \: \boxed{ \sf{Surface \: Area_{(Sphere)}= 4\pi r {}^{2} }}$

where ,

• r refers to radius

• π is mathematical constant whose value is equal to 3.14

$\sf{ \dashrightarrow \: \: \: 4\pi r {}^{2} = 314}$

$\sf{ \dashrightarrow \: \: \: 4 \times 3.14 \times r {}^{2} = 314}$

$\sf{ \dashrightarrow \: \: \:r {}^{2} = \dfrac{314}{4 \times 3.14}}$

$\sf{ \dashrightarrow \: \: \:r {}^{2} = \dfrac{ \cancel{314} \times \red{ \cancel{100}}}{ \red{ \cancel{4 }}\times \cancel{314}}}$

We get ,

$\sf{ \dashrightarrow \: \: \:r {}^{2} = 25}$

$\sf{ \dashrightarrow \: \: \:r = \sqrt{ 25}}$

$\sf{ \dashrightarrow \: \: \:\underline{ \boxed{\bold{r = 5 \: \: cm}}}} \:\:\: \bigstar$

>>> Therefore, radius of sphere is "5 cm".