It is required to make a closed cylindrical tank of height 1 m and base diameter 140 cm from a metal sheet. How many square meters of the sheet are required for the same?
Height (h) of cylindrical tank = 1 m
Base radius (r) of cylindrical tank = (
) cm
= 70 cm
= 0.7 m
Area of sheet required = Total surface area of tank
= 2
r (r + h)
= [2 * 
* 0.7 (0.7 + 1)] m2
= (4.4 * 1.7) m2
= 7.48 m2
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