Question

FIND THE RADIUS OF SPHERE WHOSE SURFACE AREA IS 154CM Sq.​

Answer 1

$\huge{ \bf{ \blue{ \mid{ \underline{ \overline{ \green{work \: out...}}}}}}}$

$\large{ \bold{you \: must \: know... }}\\ \boxed{ \large{ \red{surface \: area \: of \: sphere = 4\pi {r}^{2}}}}$

$\large{given ....} \\ \large{ = > 4\pi {r}^{2} = 154 \: {cm}^{2} } \\ \large{ = > 4 \times \frac{22}{7} \times {r}^{2} = 154 \: {cm}^{2}} \\ = > \large{{r}^{2} = \frac{154 \times 7}{4 \times 22} \: {cm}^{2}} \\ = > \large{ {r}^{2} = \frac{49}{4} {cm}^{2}} \\ \large{ = > r = \sqrt{ \frac{49}{4} } cm }\\ \large{ \green{ = > r = \frac{7}{2} cm = 3.5cm}}( \blue{answer..})$

$\large{ \bold{ \purple{running \: in \: a \: endless \: maze...}}}$

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Answer 2

⠀⠀⠀⠀$\huge\underline{ \overline{ \bf{ \purple{QUESTION}}}}$

FIND THE RADIUS OF SPHERE WHOSE SURFACE AREA IS 154CM Sq.

__________________________

⠀⠀⠀⠀⠀$\huge\underline{ \underline{ \bf{ \blue{ \: solution \: : = }}}}$

$\large\underline{ \underline{ \green{ \bold {Given}}}} = >$

$\bf \: area \: of \: sphere = 154 {cm}^{2}$

We know that,

⠀⠀${ \pink{ \boxed{ \fbox{ \bf{ \red{area \: of \: sphere = 4 \pi {r}^{2} }}}}}}$

Now,

⠀⠀⠀$\large\underline{ \underline{ \green{ \bold {</strong><strong>Acco</strong><strong>rding</strong><strong> </strong><strong>\</strong><strong>:</strong><strong>to</strong><strong> </strong><strong>\</strong><strong>:</strong><strong>question</strong><strong>}}}} = >$

⠀⠀⠀$</strong><strong>\bf</strong><strong>=</strong><strong>></strong><strong>4 \pi {r}^{2} = 154 {cm}^{2} \\ \\ \bf</strong><strong>=</strong><strong>></strong><strong>4 \times \frac{22}{7} \times {r}^{2} = 154 \\ \\ \bf </strong><strong>=</strong><strong>></strong><strong>{r}^{2} = \frac{154 \times 7}{4 \times 22} \\ \\ \bf </strong><strong>=</strong><strong>></strong><strong>{r}^{2} = \sqrt{ \frac{49}{4} } \\ \\ { \boxed{ \fbox{ \bf{\sqrt{49} =7 \: and \: \sqrt{4} = 2 }}}} \\ \\ { \boxed{ \fbox{ \purple{\bf {r}= \frac{7}{4} \: or \:r = 3.5cm }}}}$