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Question
Curved surface area of a cone is 308 cm2 and its slant height is 14 cm. Find the radius of the base and total surface area of the cone.
Solution
(1) Given that,
Slant height of cone= 14cm
Let radius of circular end of cone=r
Curved surface area of cone=`pirh`
`308cm^2=(22/7xxrxx14)cm` [∵` CSA=308 cm^2`]
⇒ `r= 308/44cm=7cm`
Thus, radius of circular end of cone= 7cm
(ii) Given that CSA= `308cm^2`
WKT, total surface area of cone
=curved surface area of cone + area of base
= `pirl+pir^2`
=`[308+22/7(7)^2]cm^2`
= `308+154cm^2`
= `462cm^2`
Thus, the total SA of the cone is `462 cm^2`
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