Question

Find the area of the sheet required to make a cyclindrical container which is
open at one side and whose diameter is 28 cm and height is 20 cm. Find the
approximate area of the sheet required to make a lid of height 2 cm for this
container.
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Answer 1

Answer:

Find the area of the sheet required to make a cyclindrical container which is

open at one side and whose diameter is 28 cm and height is 20 cm. Find the

approximate area of the sheet required to make a lid of height 2 cm for this

container.

Answer 2

Answer:

The area of the sheet required to make the cylindrical container is 2376 sq. cm and the approximate area of the sheet required to make the lid is 792 sq. cm

EXPLANATION:

Given: For cylindrical container: diameter (d) = 28 cm, height (h1) = 20 cm

For cylindrical lid: height (h2) = 2 cm 

diameter (d) = 28 cm 

∴ radius (r) = d/2 = 28/2 = 14 cm 

i. Surface area of the cylinder with one side open = Curved surface area + Area of a base 

= 2πrh1 + πr2 

= πr (2h1 + r)

= (22/7) x 14 x (2 x 20 + 14) 

= 22 x 2 x (40 + 14) 

= 22 x 2 x 54  = 2376 sq.cm

ii. Area of sheet required to made a lid = Curved surface area of lid + Area of upper surface 

= 2πrh + πr2 = πr (2h + r)

  = (22/7) x 14 x (2 x 2 + 14)

= 22 x 2 x (4 + 14) 

= 22 x 2 x 18 

= 792 sq cm.