Q3 of 67 Page 190

The area of circular base of a cylinder is 154 cm2 and its height is 21 cm. Find the volume and curved surface area of the cylinder.

Area of circular base = 154 cm2


Height = h = 21 cm


Let r be radius of circular base


Area = πr2


⇒


⇒ = r2


⇒ r2 = 7 × 7 = 49


⇒ r = ± 7


Radius cannot be negative hence r = 7


Volume of cylinder = πr2h


= × 72 × 21


= 7 × 21 × 22


= 3234 cm3


Curved surface area of cylinder = 2πrh


= 2 × × 7 × 21


= 14 × 22 × 3


= 924 cm2


Therefore, volume of cylinder is 3234 cm3 and curved surface area is 924 cm2


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