Question

A closed cylindrical tank of radius 7 m and height 3 m is made from a sheet of metal. How much sheet of metal is required?

Answer 1

Given,
Radius of cylindrical tank (r) = 7 m
Height of cylindrical tank (h) = 3 m
Total surface area of cylindrical tank = 2$\pi$ r(h+r)
$=2\times \frac{22}{7}\times 7(3+7)=44\times 10=440m^2$
Hence, $440m^2$ metal sheet is required.