Question

a rectangular piece of paper is 22 cm and 10 cm in width and it is rolled into a cylinder along its length find the surface area of the cylinder​

Answer 1

$\textbf{\underline{\underline{According\:to\:the\:Question}}}$

★Circumference = 22 cm

★Height of cylinder = 10 cm

${\boxed{\sf\:{Therefore,}}}$

★Circumference = 22 cm

⇒ 2πr = 22

$\tt{\rightarrow 2\times\dfrac{22}{7}\times r=22}$

$\tt{\rightarrow r=\dfrac{7}{2}}$

= 3.5 cm

★Now,

Curved Surface Area of cylinder = 2πrh

$\tt{\rightarrow 2\times\dfrac{22}{7}\times 3.5\times 10}$

= 220 cm²

${\boxed{\sf\:{Total\;Surface\;Area}}}$

$\tt{\rightarrow 220+2\times\dfrac{22}{7}\times 3.5^2}$

= 220 + 77

= 297 cm²

Answer 2

Answer:

$\displaystyle{Total \ surface \ area=297 \ cm^2}$

Step-by-step explanation:

Given ;

Length and breadth of rectangle 22 cm and 10 cm respectively .

When it will fold into cylinder form then length will become

perimeter i.e. circumference and breadth become height .

Now , We have to find total surface area .

$\displaystyle{Total \ surface \ area=2\pi r(r+h)}$

Let find radius ( r ) .

$\displaystyle{2\pi r = 22}\\\\\\\displaystyle{r=3.5 \ cm}$

Now putting value in formula

$\displaystyle{Total \ surface \ area=2\times22/7\times3.5(3.5+10)}\\\\\\\displaystyle{Total \ surface \ area=55\times13.5}\\\\\\\displaystyle{Total \ surface \ area=297 \ cm^2}$

Thus we get answer .