Question

A metal pipe is 77 cm77 cm long. The inner diameter of a cross-section is 4 cm4 cm, the outer diameter being 4.4 cm,4.4 cm then find its outer curved surface area.

Answer 1

Dimensions be :

$\Rightarrow R=$ outer radius $=\frac{4.4}{2}=2.2cm$

$r=$ Inner radius $=\frac{4}{2}=2cm$

$\Rightarrow$ Height $h=77cm$

$\therefore$ Outer curved surface area $=2\pi Rh$

$=2\times \frac{22}{7}\times 2.2\times 77$

$=1064.8c{m}^2$

$\therefore$ Outer curved surface area $=1064.8c{m}^2.$

Hence, the answer is $1064.8c{m}^2.$