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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 = 2.5 cm, h = 7 cm
उत्तर
We know that,
Curved surface area = 2πrh
Total surface area = 2πr(h + r)
Here, r = 2.5 cm, h = 7 cm
Curved surface area of a cylinder = 2πrh
= `2 xx 22/7 xx 2.5 xx 7`
= `44 xx 2.5`
= 110 sq.cm.
Total surface area of a cylinder = 2πr(h + r)
= `2 xx 22/7 xx 2.5(7 + 2.5)`
= `110/7 xx 9.5`
= `1045/7 = 149.285`
≈ 149.29 sq. cm.
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