A cylinder has a height of 15 feet and a radius of 4 feet. Solve for the total surface area of the cylinder. Use 3.14 for π and round to the nearest tenth.

1. 477.3 feet2
2. 60 feet2
3. 56.52 feet2
4. 301.44 feet2

1 answer

To find the total surface area (SA) of a cylinder, we can use the formula:

\[ SA = 2\pi r^2 + 2\pi rh \]

where:

  • \( r \) is the radius of the base,
  • \( h \) is the height of the cylinder,
  • \( \pi \) is approximately 3.14.

Given:

  • \( r = 4 \) feet
  • \( h = 15 \) feet

Now we will calculate each part of the formula.

  1. Calculate the area of the two circular bases: \[ 2\pi r^2 = 2 \times 3.14 \times (4^2) \] \[ = 2 \times 3.14 \times 16 \] \[ = 2 \times 3.14 \times 16 = 100.48 \text{ feet}^2 \]

  2. Calculate the lateral surface area: \[ 2\pi rh = 2 \times 3.14 \times 4 \times 15 \] \[ = 2 \times 3.14 \times 60 \] \[ = 2 \times 188.4 = 376.8 \text{ feet}^2 \]

  3. Now, add both areas together to get the total surface area: \[ SA = 100.48 + 376.8 = 477.28 \text{ feet}^2 \]

Rounding to the nearest tenth, we have: \[ SA \approx 477.3 \text{ feet}^2 \]

Thus, the correct answer is:

  1. 477.3 feet².