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प्रश्न
In the example given below, the radius of the base of a cylinder and its height is given. Then find the curved surface area and total surface area.
r = 1.4 cm, h = 2.1 cm
उत्तर
Given: r = 1.4 cm and h = 2.1 cm
Curved surface area of cylinder and total surface area
Curved surface area of the cylinder = 2πrh
= `2 xx 22/7 xx 1.4 xx 2.1`
= `2 xx 22 xx 0.2 xx 2.1`
= 18.48 sq. cm
Total surface area of the cylinder = 2πr (h + r)
= `2 xx 22/7 xx 1.4(2.1 + 1.4)`
= `2 xx 22/7 xx 1.4 xx 3.5`
= `2 xx 22 xx 0.2 3.5`
= `30.80` sq. cm
∴ The curved surface area of the cylinder is 18.48 sq. cm and its total surface area is 30.80 sq. cm.
संबंधित प्रश्न
The students of a Vidyalaya were asked to participate in a competition for making and decorating penholders in the shape of a cylinder with a base, using cardboard. Each penholder was to be of radius 3 cm and height 10.5 cm. The Vidyalaya was to supply the competitors with cardboard. If there were 35 competitors, how much cardboard was required to be bought for the competition?
`["Assume "pi=22/7]`
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