Question

It is required to make a closed cylindrical tank of height $1m$ and base diameter $140cm$ from a metal sheet. How many square meters of the sheet are required for the same? Assume $\pi =\frac{22}{7}$

Answer 1

Find the sheet required to make cylinder :

Given,

Height of cylindrical tank $\left(h\right)$ $=1m$

Base diameter of cylinder $\left(d\right)$ $=140cm$

So, radius of cylinder $\left(r\right)$ $=\frac{d}{2}=\frac{140}{2}=70cm=0.7m$

Area of metal sheet required $=$ Total surface area of the cylindrical tank

$=2\pi r(r+h)$

$=2\times \frac{22}{7}\times 0.7\times (0.7+1)$

$=7.48m^2$

Hence, $7.48m^2$ of sheet is required to make the cylinder.