If the height of a cone is 16 cm and its base radius is 12 cm, then its curved surface area is (use \(\pi=3.14\)):
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → 753.6 cm2
The curved surface area of a cone is \(\pi rl\), where \(l\) is the slant height. The height, the radius and the slant height form a right triangle, so \(l\) comes from Pythagoras’ theorem.
Slant height, by Pythagoras’ theorem: \(l=\sqrt{16^2+12^2}=\sqrt{400}=20\) cm
Curved surface area \(=3.14\times12\times20=753.6\) cm2