As you'll see in the following practice questions, you may be asked to calculate a cone's surface area (in this case, based on its lateral area and base area) or its volume (in this case, given its radius and slant height).

## Practice questions

- A cone has a lateral area of and a base area of .
How many square centimeters is the surface area of the cone?

*Refer to the following figure for the next question.* - What is the volume of the cone?

## Answers and explanations

- The correct answer is Choice
**(E).**The surface area of a cone is the sum of its lateral area*(L)*and base area. A cone has only one base, so you add*B*to the lateral area instead of 2*B*.The surface area of the cone is

- The correct answer is Choice
**(B).**The volume of a cone is a third of the product of its base and its height. The height of this cone isn't given, but you can use the Pythagorean theorem to find it. The height, a radius, and the slant height form a right triangle in which the height and the radius are perpendicular and the slant height is the hypotenuse.The height of the cone is 24 m. That times a third of the base area is the volume of the cone:

The volume of the cone is