Question

Curved surface area of a cone is 308 cm2 and its slant height is 14 cm. Find:
(i) radius of the base.
(ii) total surface area of the cone.

Answer 1

given :-

curved surface area of the cone = 308cm²

slant height (l) of the cone = 14cm

(i) we know the formula for the CSA of a cone is πrl

therefore πrl = 308cm²

==> 22/7 × r × 14 = 308cm²

==> 22 × r × 2 = 308cm²

==> 44 × r = 308cm²

==> r = 308/44

==> r = 7

hence, the radius of the cone is 7cm.

(ii) to find the TSA of a cone we use πrl + πr² as we know the base of a cone is circular.

therefore it's TSA = πrl + πr²

= ( 22/7 × 7 × 14 ) + ( 22/7 × 7 × 7 )

= ( 22 × 14 ) + ( 22 × 7 )

= 308 + 154

= 462cm²

HOPE THIS HELPS..!!

Answer 2

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TSA of cone = 462 cm²