The radius of the base of a right circular cone is 5 cm. Its slant height is 13 cm. What is its volume (in cm3, rounded off to 1 decimal place)?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 314.3.
The radius of the base of a right circular cone (r) = 5 cm
Its slant height (l) = 13 cm
Volume of a cone = ⅓ 𝜋r2h cubic units
r is the radius of the circular base and h is the height of the cone
l = √(r2 + h2)
⇒ 13 = √(52 + h2)
⇒ 169 = 25 + h2
⇒ h2 = 169 - 25 = 144
⇒ h = 12 cm
Volume of a cone = ⅓ 𝜋r2h = (1/3) × (22/7) × 25 × 12 = 314.3 cm3