Question

the ratioof the whole surface area of a solid sphere and a solid hemisphere is ............​

Answer 1

$\huge \bf \mathfrak \green {answer : }$

$\huge \bf \orange{4:3}$

$\bf \purple{STEP-BY-STEP \: \: VERIFICATION:}$

WE KNOW THAT,

T. S. A. of sphere

$= \green{4\pi {r}^{2} }$

T. S. A. of hemisphere

$= \blue{3\pi {r}^{2} }$

RATIO OF T. S. A. OF SPHERE TO THAT OF HEMISPHERE

$= \red{ 4\pi {r}^{2} : 3\pi {r}^{2} }$

$= \huge\bf\mathfrak{ 4 : 3}$

Answer 2

We know that T.S.A of sphere is

$4\pi \: r2$

$3\pi \: r2$

T.S.A of hemisphere.

therefore Ratio of T.S.A of sphere and hemisphere is,

4π r2 : 3π r2

4:3.

hope it helps...