the outer diameter of metallic pipe is 18cm and the thickness of pipe

1.	the outer diameter of metallic pipe is 18cm and the thickness of pipe is 2cm and the height is 4cm. find the surface area of the metallic pipe
Answer» Given, OUTER diameter = 18 cm Thickness = 2 cm Height = 4 cm To find :- The SURFACE area of metallic pipe. Solution :- Given, Outer diameter = 18 cm $\large \rm Radius ( R ) \: outer \: radius = \frac {d}{2} \\ \implies \large \rm \frac {\cancel{18}\: \: ^{<klux>9</klux>}}{\cancel2}\\ \\ \large \rm \therefore R = 9 cm$ Thickness = 2 cm The inner radius = 9 - 2 = 7 cm Height of the pipe = 4 cm $\sf\underline\blue{ The \: metallic \: pipe \: has \: the \: shape \: of \: cylinder }$ Surface area of outer pipe = $\rm 2 \pi Rh$ $\implies \: 2\pi \times 9 \times 4$ $\bf \: outer \: area = 72\pi {cm}^{2}$ Inner surface area of pipe = $\rm 2 \pi rh$ $\implies\rm \: 2 \times \pi \times 7 \times 4$ $= \bf \: 56\pi {cm}^{2}$ Now, The surface area of metallic pipe = 2πRh - 2πrh $\implies \bf \: 72\pi - 56\pi \\ \bf \implies \: Area = 16\pi{cm}^{2}$ Henceforth, $\sf \blue{The \: surface \: area \: of \:metallic \: pipe \: = 16\pi {cm}^{2} }$ ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ $\large\fbox \red {Hope \: it \: helps \: you}$

the outer diameter of metallic pipe is 18cm and the thickness of pipe is 2cm and the height is 4cm. find the surface area of the metallic pipe

Answer»

Given,

OUTER diameter = 18 cm
Thickness = 2 cm
Height = 4 cm

To find :-

The SURFACE area of metallic pipe.

Solution :-

Given,

Outer diameter = 18 cm

$\large \rm Radius ( R ) \: outer \: radius = \frac {d}{2} \\ \implies \large \rm \frac {\cancel{18}\: \: ^{<klux>9</klux>}}{\cancel2}\\ \\ \large \rm \therefore R = 9 cm$