Question

Find the radius of a sphere whose surface Area is 154cm. ​

Answer 1

Answer:

3.5 cm

Step-by-step explanation:

Given,

Surface area of sphere= 154 cm²

We know,

4πr²= 154(as surface area of sphere= 4πr²)

Or, πr²= 38.5

Or,r²= 38.5*7/22

Or,r²= 12.25

Or,r= 3.5.

Hence, radius of sphere = 3.5 cm

Answer 2

Given,

Surface area of sphere is 154 cm^2

Surface area of sphere = 4πr^2

$4 \times \frac{22}{7} \times {r}^{2} = 154\\ {r}^{2} = \frac{154}{4} \times \frac{7}{22}\\{r}^{2} = \frac{49}{4} \\r = \sqrt{ \frac{49}{4} }\\r = \frac{7}{2}\\r= 3.5cm$

Therefore the radius is 3.5cm.