Question

Find the radius of a sphere, whose surface area is 154cm^2

Answer 1

Answer:

Step-by-step explanation:

Surface ara of sphere =4pi r

4pi r= 154

Therefore, 4×22/7×r = 154

88r = 154×7

r =1078/88

r =12.25

Answer 2

$\mathfrak{Answer:}$

= 3.5 cm.

$\mathfrak{Step-by-Step\:Explanation:}$

$\underline{\bold{Given\:in\:the\:Question:}}$

• Surface area of the sphere = 154 cm².

$\underline{\bold{To\:find;}}$

• The radius of the sphere = ?

$\bold{Solution:}$

Let the radius of the sphere be r cm.

$\mathfrak{According\:to\:Question:}\\\\\\\boxed{\bold{Surface\:Area\:of\:the\:sphere=4\pi r^2.}}\\\\\\\implies\tt{4\pi r^2=154}\\\\\\\implies\tt{r^2=\dfrac{154}{4\pi}}\\\\\\\implies\tt{r^2=\dfrac{154}{4}\times\dfrac{7}{22}}\\\\\\\implies\tt{r^2=\dfrac{49}{4}}\\\\\\\implies\tt{r=\pm\dfrac{7}{2}=\pm 3.5}\\\\\\\underline{\bold{Possible\:value\:of\:r=3.5\;cm.}}\\\\\\\\\boxed{\boxed{\bold{Radius=3.5\:cm.}}}$