Ex 9.2, 7 - Chapter 9 Class 8 Mensuration

Transcript

Ex 9.2, 7 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?Here, sheet is in shape of a rectangle Given that Closed cylindrical tank is made of sheet of metal ∴ Area of metal sheet = Area of Closed Cylindrical Tank = Total Surface Area of Cylinder In Cylinder, Radius = r = 7 m Height = h = 3 m Total Surface Area of Cylinder = 2𝜋𝑟(ℎ+𝑟) = 𝟐 × 𝝅 × 𝟕 × (𝟑+𝟕) = 2 × 𝜋 × 7 × 10 = 2 × 22/7 × 7 × 10 = 2 × 22 × 10 = 𝟒𝟒𝟎 𝒎^𝟐 ∴ Required area is 𝟒𝟒𝟎〖 𝒎〗^𝟐