What is the surface area of a cone to the nearest foot with a radius of 4 ft. and a slant height of 10 ft.?(1 point)

1 answer

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

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

where \( r \) is the radius and \( l \) is the slant height.

In this case:

  • \( r = 4 \) ft
  • \( l = 10 \) ft

Now, substitute these values into the formula:

\[ \text{Surface Area} = \pi \times 4 \times (4 + 10) \] \[ = \pi \times 4 \times 14 \] \[ = \pi \times 56 \]

Now, calculate this using an approximate value for \(\pi \) (around 3.14):

\[ \text{Surface Area} \approx 3.14 \times 56 \approx 175.84 \]

Rounding to the nearest foot, the surface area of the cone is approximately:

\[ \text{Surface Area} \approx 176 \text{ ft}^2 \]

So, the surface area of the cone is 176 ft².