Question

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

• A. \( \pi r l + r \)
• B. \( \pi r l + \pi r^2 \)
• C. \( \pi r^2 + r^2 \)
• D. \( \pi r l + 2r^2 \)

Hint:

The total surface area of a cone is the sum of the curved surface area \( \pi r l \) and the area of the base \( \pi r^2 \).

Answer 1

The Correct Option is B

The total surface area \( A \) of a cone is given by: \[ A = \pi r l + \pi r^2, \] where \( r \) is the radius and \( l \) is the slant height. Thus, the total surface area of the cone is \( \boxed{\pi r l + \pi r^2} \).