What is the surface area of this cylinder? The radius is 5.1 mm and the height is 4 mm 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 about _____ square millimeters

1 answer

To find the surface area of the cylinder, we will calculate the areas of the top, bottom, and curved surface using the given radius and height.

  1. Given Values:

    • Radius (r) = 5.1 mm
    • Height (h) = 4 mm
    • Use \( \pi \approx 3.14 \)
  2. Calculate the Area of the Top and Bottom Circles: \[ A_{\text{top}} = A_{\text{bottom}} = \pi r^2 \] \[ A_{\text{top}} = A_{\text{bottom}} = 3.14 \times (5.1)^2 \] \[ = 3.14 \times 26.01 \approx 81.77 \text{ mm}^2 \]

    Since there are two circles (top and bottom): \[ A_{\text{top}} + A_{\text{bottom}} = 81.77 + 81.77 = 163.54 \text{ mm}^2 \]

  3. Calculate the Circumference of the Top Circle: \[ C = 2 \pi r \] \[ = 2 \times 3.14 \times 5.1 \] \[ \approx 31.94 \text{ mm} \]

  4. Calculate the Area of the Curved Surface:

    • The curved surface can be represented as a rectangle where one side is the height and the other side is the circumference of the circle. \[ A_{\text{curved}} = C \times h \] \[ = 31.94 \times 4 \] \[ \approx 127.76 \text{ mm}^2 \]
  5. Total Surface Area of the Cylinder: \[ \text{Surface Area} = A_{\text{top}} + A_{\text{bottom}} + A_{\text{curved}} \] \[ = 163.54 + 127.76 \] \[ = 291.30 \text{ mm}^2 \]

Finally, rounding to the nearest hundredth, the surface area of the cylinder is approximately 291.30 square millimeters.