A spyglass in the shape of a cone has a slant height of 18 centimeters and a radius of 6 centimeters. What is the surface area of the spyglass? Use 3.14 for pi.

1. 1,356.48 square centimeters
2. 339.12 square centimeters
3. 197.82 square centimeters
4. 452.16 square centimeters

1 answer

The surface area of a cone can be found using the formula A = πr^2 + πrℓ, where r is the radius and ℓ is the slant height.

Plugging in the values given, we have A = 3.14(6^2) + 3.14(6)(18).

Simplifying, we get A = 3.14(36) + 3.14(108).

A = 113.04 + 339.12.

A = 452.16.

Therefore, the surface area of the spyglass is 452.16 square centimeters.

The correct answer is 4. 452.16 square centimeters.