Question

It is required to make a closed cylindrical tank of height 1 m and the base diameter of 140 cm from a metal sheet. How many square meters of the sheet are required for the same?

Answer 1

Height of cylindrical tank (h) = 1 m

Base radius of cylindrical tank (r) = diameter/2 

= 140/2 cm 

= 70 cm 

= 0.7 m 

[1 m = 100 cm] 

Now, 

Area of sheet required = Total surface area of tank (TSA) = 2πr(h + r) 

=2 x 3.14 x 0.7(1 + 0.7) 

= 7.48 

Therefore, 7.48 m² metal sheet is required to make required closed cylindrical tank.