What are the different way for solving the question for class 9th question of Surface Areas and Volumes chapter of math of question no.3 of math please suggest me the best way for solving this question of exercise 13.3 Curved surface area of a cone is 308 cm2 and its slant height is 14 cm. Find (i) radius of the base and (ii) total surface area of the cone. (Assume π = 22/7)
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Curved surface area of a cone is 308 cm2 and its slant height is 14 cm. Find (i) radius of the base and (ii) total surface area of the cone. (Assume π = 22/7) Q.3
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Slant height of cone, l = 14 cm
Let the radius of the cone be r.
(i) We know, CSA of cone = πrl
Given: Curved surface area of a cone is 308 cm2
(308 ) = (22/7)×r×14
308 = 44 r
r = 308/44 = 7
Radius of a cone base is 7 cm.
(ii) Total surface area of cone = CSA of cone + Area of base (πr2)
Total surface area of cone = 308+(22/7)×72 = 308+154
Therefore, the total surface area of the cone is 462 cm2.