The area of the base of a right circular cone is 308 cm2, and its height is cm. Find its curved surface area (in cm2). (Use π = 22/7)
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. .
πr2 = 308
⇒ (22/7) × r2 = 308
⇒ r = √98 = 7√2 cm
Slant height (l) = √[(7√2)2 + (7√2)2] = √196 = 14 cm
Curved surface area = πrl = (22/7) × 7√2 × 14 = 308√2 cm2