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Question
A toy is in the form of a cone mounted on a hemisphere of common base radius 7 cm. The total height of the toy is 31 cm. Find the total surface area of the toy.
Solution
Radius of the common base of the hemisphere and cone = 7 cm
Curved surface area of the hemisphere `= 2pir^2 = 2xx22/7xx7xx7 = 308` cm2
`"Height of the cone = Total height - Radius =31 - 7 =24 cm"`
`"Curved surface area of the cone" = pirl = pirlsqrt(r^2 + h^2) = 22/7 xx 7sqrt(49 + 576)=22sqrt(625) = 22xx25 = 550` cm2
Total surface area of the toy = 550 + 308 = 858 Cm2
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