The circumference of the base of a right circular cone is 88 cm. If the height of the cone is 28 cm, then what is the curved surface area of the cone?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is Option 2 i.e. 616√5 cm2.
2πr = 88
⇒ 2 × (22/7) × r = 88
⇒ r = 14 cm
Slant height (l) = √(r2 + h2) = (142 + 282) = √980 = 14√5 cm
Curved surface area of the cone = πrl = (22/7) × 14 × 14√5 = 616√5 cm2