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प्रश्न
Find the surface area of a sphere of radius 3.5 cm.
उत्तर
Radius (r) of sphere = 3.5 cm
∴ Surface area = 4πr2
`= 4 xx 22/7 xx 3.5 xx 3.5`
`= 88 xx 1.75`
= 154 cm2
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