Find the area of the sheet required to make a cylindrical 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 .
Dimensions of the cylindrical container:
diameter ( d ) = 28 cm
radius ( r ) = d/2 = 28/2 = 14 cm
Height ( H ) = 20 cm
Area of the sheet required to make the
container ( A ) = base area + L.S.A
= πr² + 2πrH
= πr( r + 2H )
= ( 22/7 ) × 14 [ 14 + 2 × 20 ]
= 22 × 2 × 54
= 2376 square centimetres
ii ) Dimensions of the lid :
radius( r ) = 14 cm
height ( h ) = 2 cm
Area of the sheet required to make the lid = πr( r + 2h )
= ( 22/7 ) × 14 [ 14 + 2 × 2 ]
= 22 × 2 × 18
= 792 cm²