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प्रश्न
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?
उत्तर
Radius of tank (r) = 7 m
Height of tank (h) = 3 m
Then total surface area of this tank = 2πr(h + r)
= `2 × 22/7 × 7 (3 + 7)`
= 44 × 10
= 440 m2
Hence, quantity of desired metal sheet = 440 m2
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