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प्रश्न
The volume of a hemisphere is 2425 `1/2` cm3 . Find its curved surface area.
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उत्तर
As , volume of hemisphere = 2425`1/2`cm3
⇒ `2/3 pir^3 = 2425 1/2`
⇒ `2/3 xx 22/7 xx r^3 = 4851/2`
⇒ `r^3 = (4851 xx 3 xx 7)/(2 xx 2 xx 22)`
⇒ `r^3 = (441 xx 3 xx 7)/(2 xx 2 xx 2)`
⇒ `r^3 = 21^3/2^3`
⇒ `r = 21/2` cm
So , the curved surface area of the hemisphere = `2pir^2`
= `2 xx 22/7 xx 21/2 xx 21/2`
= 693 cm2
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