Determine the surface area of a cone if the diameter of the base is 14 ft., and the slant height of the cone is 19 ft. Use π=3.14 and round your answer to the nearest hundredth.(1 point)

1 answer

To determine the surface area of a cone, we 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.

First, we need to find the radius of the base. The diameter of the base is given as 14 ft, so the radius \( r \) is:

\[ r = \frac{\text{diameter}}{2} = \frac{14 \text{ ft}}{2} = 7 \text{ ft} \]

Next, we know the slant height \( l \) is 19 ft.

Now we can substitute \( r \) and \( l \) into the surface area formula:

  1. Calculate the area of the base:

\[ \pi r^2 = 3.14 \times (7 \text{ ft})^2 = 3.14 \times 49 \text{ ft}^2 = 153.86 \text{ ft}^2 \]

  1. Calculate the lateral surface area:

\[ \pi r l = 3.14 \times 7 \text{ ft} \times 19 \text{ ft} = 3.14 \times 133 \text{ ft}^2 = 417.82 \text{ ft}^2 \]

  1. Now, add both areas together to find the total surface area:

\[ \text{Surface Area} = 153.86 \text{ ft}^2 + 417.82 \text{ ft}^2 = 571.68 \text{ ft}^2 \]

Finally, rounding to the nearest hundredth, the surface area of the cone is:

\[ \boxed{571.68} \text{ ft}^2 \]