Question

What is the surface area, in square inches, of a cone with a radius of 10 inches and a slant height of 15 inches? Use 3.14 for pi.(1 point)Responses2,198 square inches2,198 square inches1,177.5 square inches1,177.5 square inches471 square inches471 square inches785 square inches

Answer 1

To calculate the surface area of a cone, we use the formula:

\[
\text{Surface Area} = \pi r (r + l)
\]

where:
- \( r \) is the radius,
- \( l \) is the slant height,
- \( \pi \) is approximately 3.14.

Given:
- Radius \( r = 10 \) inches,
- Slant height \( l = 15 \) inches.

Now, we can substitute these values into the formula:

\[
\text{Surface Area} = 3.14 \times 10 \times (10 + 15)
\]

Calculating \( (10 + 15) \):

\[
10 + 15 = 25
\]

Now substitute back into the formula:

\[
\text{Surface Area} = 3.14 \times 10 \times 25
\]

Calculating \( 10 \times 25 \):

\[
10 \times 25 = 250
\]

Now multiply by \( 3.14 \):

\[
\text{Surface Area} = 3.14 \times 250 = 785
\]

Thus, the surface area of the cone is:

\[
\text{Surface Area} = 785 \text{ square inches}
\]

The correct response is **785 square inches**.