The area of the base of a cone is 314 cm² and the curved surface area is 628 cm². The volume of this cone will be (take \(\pi \) = 3.14)?
Answer & explanation
Correct answer: option 4
Area of base = \(\pi \)r2
⇒ 314 = \(\pi \)r2
⇒ r = 10 cm (Take \(\pi \) = 3.14)
C.S.A. = \(\pi \)rl
⇒ 628 = 3.14 × 10 × l
⇒ l = 20 cm
h = \(\sqrt {l^2 - r^2}\) = \(\sqrt {400 - 100}\) = \(\sqrt {300}\) = 10\(\sqrt{3}\)
Volume = \(\frac{1}{3}\) \(\pi \)r2h
= \(\frac{1}{3}\) × 3.14 × 100 × 10\(\sqrt{3}\) = \(\frac{3140\sqrt {3}}{3}\) cm3