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

height is 22 cm
d=25 cm

3 answers

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 of the cone
  • \(l\) is the slant height of the cone
  1. Calculate the radius (r): Given the diameter \(d = 25\) cm, the radius \(r\) is: \[ r = \frac{d}{2} = \frac{25}{2} = 12.5 \text{ cm} \]

  2. Calculate the slant height (l): The slant height can be calculated using the Pythagorean theorem. Given the height \(h = 22\) cm: \[ l = \sqrt{r^2 + h^2} \] Plugging in the values: \[ l = \sqrt{(12.5)^2 + (22)^2} = \sqrt{156.25 + 484} = \sqrt{640.25} \approx 25.25 \text{ cm} \]

  3. Calculate the surface area: Now we can substitute \(r\) and \(l\) into the surface area formula: \[ \text{Surface Area} = \pi r^2 + \pi r l \] \[ \text{Surface Area} = 3.14 \times (12.5)^2 + 3.14 \times 12.5 \times 25.25 \]

    Calculating \( \pi r^2 \): \[ 3.14 \times (12.5)^2 = 3.14 \times 156.25 = 490.625 \]

    Calculating \( \pi r l \): \[ 3.14 \times 12.5 \times 25.25 \approx 3.14 \times 316.25 \approx 995.325 \]

    Now, adding these two areas together: \[ \text{Surface Area} = 490.625 + 995.325 = 1485.95 \text{ square centimeters} \]

Thus, the approximate surface area of the cone is 1485.95 square centimeters.

It appears that none of the provided options match this result, please double-check the parameters or the options given.

width is 25 cm, height is 22 cm

If by "width" you mean the diameter of the base of the cone, let's clarify the calculations for the surface area of the cone with the given height and diameter.

  1. Given:

    • Height (\(h\)) = 22 cm
    • Diameter (\(d\)) = 25 cm
  2. Calculate the radius (\(r\)): \[ r = \frac{d}{2} = \frac{25}{2} = 12.5 \text{ cm} \]

  3. Calculate the slant height (\(l\)): Use the Pythagorean theorem: \[ l = \sqrt{r^2 + h^2} \] \[ l = \sqrt{(12.5)^2 + (22)^2} = \sqrt{156.25 + 484} = \sqrt{640.25} \approx 25.25 \text{ cm} \]

  4. Surface Area Formula: The surface area (\(SA\)) of a cone is given by: \[ SA = \pi r^2 + \pi r l \]

  5. Calculating the Base Area (\( \pi r^2 \)): \[ \pi r^2 = 3.14 \times (12.5)^2 = 3.14 \times 156.25 \approx 490.625 \text{ cm}^2 \]

  6. Calculating the Lateral Area (\( \pi r l \)): \[ \pi r l = 3.14 \times 12.5 \times 25.25 \] First calculate \( r \times l \): \[ 12.5 \times 25.25 = 316.25 \] Now multiply by \( \pi \): \[ \pi r l \approx 3.14 \times 316.25 \approx 995.325 \text{ cm}^2 \]

  7. Total Surface Area: \[ SA = 490.625 + 995.325 = 1485.95 \text{ cm}^2 \]

Final Surface Area: The approximate surface area of the cone is still 1485.95 square centimeters.

Comparison with Given Options:

  1. 1,354.125 square centimeters
  2. 3,689.5 square centimeters
  3. 2,383.26 square centimeters
  4. 863.5 square centimeters

No provided options match the calculated surface area. Please check the input values or clarify if additional information is needed to correct the approach.