Q16 of 18 Page 13

A rectangular sheet of metal 44 cm long and 20 cm broad is rolled along its length into a right circular cylinder so that the cylinder has 20 cm as its height. Find the volume and curved surface are of the cylinder so formed.

Length of the rectangular sheet = 44 cm
Breadth of the rectangular sheet = 20 cm
Area of the sheet = 44 × 20 = 880 sq. cm ∴ Curved surface area of the cylinder = Area of the sheet
                                                 = 880 sq. cm
                        Height of the cylinder  = 20 cm
Circumference of the cylinder = 44 cm                                  ⇒ 2π r= 44 ∴ r = = = = 7 cm ∴ Volume of the cylinder = π r2h
                                   = × 7 × 7 × 20
                                   = 3080 cu. cm ∴ Volume of the cylinder is 3080 cu. cm and the curved surface area of the cylinder is 880 sq. cm.

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