Hence, area of the steel sheet required for one basin = 2772 cm²

Total area of steel sheet required for 1000 basins      = 2772 × 1000

= 2772000 cm²

= 277.2 m²

Example-5. A5t right circular cylinder has base radius 14cm and height 21cm.

1. area of base (or area of each end)


2. curved surface area


3. total surface area and


4. volume.

Solution: Radius of the cylinder (r) = 14cm

Height of the cylinder (h) = 21cm

Now
1. Area of base (area of each end) πr²= 22/7 (14)²= 616 cm²


2. Curved surface area 2πrh × 22/7 × 14 × 21
   = 1848 cm²



3. Total surface area = 2 × area of the base + curved surface area

   = 2 × 616 + 1848 = 3080 cm²



4. Volume of cylinder = πr²h = area of the base × height

   = 616 × 21 = 12936 cm³.

Example-6. Find the volume and surface area of a sphere of radius 2.1cm (π = 22/7)

Solution:Radius of sphere (r) = 2.1cm

Surface area of sphere = 4πr²

= 4 × 22/7 × (2.1)² = 4 × 22/7 × 21/10×21/10

= 1386/25 = 55.44 cm²

Volume of sphere = 4/3 πr³ = 4/3 × 22/7 × (2.1)³