A cone shows a base diameter of 25 centimeters, perpendicular height from the base to the top vertex at 90 degrees, and 22 centimeters as the hypotenuse or the side of the cone.

What is the surface area of the cone? Use 3.14 for pi.
(1 point)
Responses

1,354.125 square centimeters
1,354.125 square centimeters
3,689.5 square centimeters
3,689.5 square centimeters
2,383.26 square centimeters
2,383.26 square centimeters
863.5 square centimeters

1 answer

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

\[ \text{Surface Area} = \pi r^2 + \pi r l \]

where:

  • \( r \) is the radius of the base,
  • \( l \) is the slant height of the cone,
  • \( \pi \) is approximately 3.14.

Given:

  • The diameter of the base is 25 cm, so the radius \( r \) is:

\[ r = \frac{25}{2} = 12.5 , \text{cm} \]

  • The slant height \( l \) is given as 22 cm.

Now, we can calculate the surface area step by step.

  1. Calculate the area of the base:

\[ \text{Base Area} = \pi r^2 = 3.14 \times (12.5)^2 \]

Calculating \( (12.5)^2 \):

\[ 12.5^2 = 156.25 \]

Thus, the base area is:

\[ \text{Base Area} = 3.14 \times 156.25 = 490.625 , \text{cm}^2 \]

  1. Next, calculate the lateral surface area:

\[ \text{Lateral Surface Area} = \pi r l = 3.14 \times 12.5 \times 22 \]

Calculating \( 12.5 \times 22 \):

\[ 12.5 \times 22 = 275 \]

So, the lateral surface area is:

\[ \text{Lateral Surface Area} = 3.14 \times 275 = 863.5 , \text{cm}^2 \]

  1. Finally, add the area of the base and the lateral surface area together to get the total surface area:

\[ \text{Total Surface Area} = \text{Base Area} + \text{Lateral Surface Area} = 490.625 + 863.5 \]

Calculating that:

\[ \text{Total Surface Area} = 1354.125 , \text{cm}^2 \]

Thus, the surface area of the cone is \( 1354.125 , \text{cm}^2 \).

The correct response is:

1,354.125 square centimeters.