What is the surface area of this cylinder? The radius is 8.1 ft and the height is 13.6 ft Surface area = Atop + Abottom + Aside Use ​𝜋 ≈ 3.14 and round your answer to the nearest hundredth. Find the radius and height of the cylinder. The circle on the bottom of the cylinder is the same, so: Find the circumference of the top circle. Now find the area of the curved surface. The curved surface is a rectangle. One side length is the height, and the other side length is the circumference of the circle. Now add the areas to find the surface area of the cylinder. The surface area of the cylinder is _____ square feet

1 answer

To find the surface area of the cylinder, we can use the formula you provided:

\[ \text{Surface Area} = A_{\text{top}} + A_{\text{bottom}} + A_{\text{side}} \]

  1. Calculate the area of the top and bottom circles (both are the same): The area \( A \) of a circle is given by:

    \[ A = \pi r^2 \]

    For the top and bottom of the cylinder, the radius \( r = 8.1 \) ft:

    \[ A_{\text{top}} = A_{\text{bottom}} = \pi (8.1)^2 \]

    Using \( \pi \approx 3.14 \):

    \[ A_{\text{top}} = A_{\text{bottom}} = 3.14 \times (8.1)^2 = 3.14 \times 65.61 \approx 206.19 \text{ square feet} \]

    Since there are two circles (top and bottom):

    \[ 2 \times 206.19 \approx 412.38 \text{ square feet} \]

  2. Calculate the circumference of the top circle: The circumference \( C \) of a circle is given by:

    \[ C = 2\pi r \]

    For the cylinder, the radius \( r = 8.1 \) ft:

    \[ C = 2 \pi (8.1) = 2 \times 3.14 \times 8.1 \approx 51.03 \text{ feet} \]

  3. Calculate the area of the curved surface (side area): The area of the side (curved surface) \( A_{\text{side}} \) of the cylinder is given by:

    \[ A_{\text{side}} = C \times h \]

    Where \( h = 13.6 \) ft:

    \[ A_{\text{side}} = 51.03 \times 13.6 \approx 694.23 \text{ square feet} \]

  4. Add all areas to find the total surface area:

\[ \text{Surface Area} = A_{\text{top}} + A_{\text{bottom}} + A_{\text{side}} = 412.38 + 694.23 \approx 1106.61 \text{ square feet} \]

  1. Rounding to the nearest hundredth:

The surface area of the cylinder is approximately 1106.61 square feet.