Question

If \( r \) is the radius of the base of a cone and \( l \) is its slant height, then the curved surface area of the cone is:

• A. \( 3 \pi r l \)
• B. \( \pi r l \)
• C. \( \frac{1}{3} \pi r l \)
• D. \( 2 \pi r l \)

Hint:

For a cone, the curved surface area is calculated using \( \pi r l \), while the total surface area includes the base and is given by \( \pi r (l + r) \).

Answer 1

The Correct Option is B

Step 1: Identify the formula The curved surface area of a cone is given by: \[ A = \pi r l \] where: - \( r \) is the radius of the base, - \( l \) is the slant height of the cone. Step 2: Conclusion Since the formula matches option (B), the correct answer is: \[ \pi r l \]