To find the surface area of the outside of the cylinder, we need to find the lateral surface area (the curved part) and the areas of the top and bottom faces.
The formula for the lateral surface area of a cylinder is: A = 2πrh, where r is the radius and h is the height.
In this case, the radius is 4 feet and the height is 3 feet. So, the lateral surface area is:
A = 2 * 3.14 * 4 * 3
= 75.36 ft² (rounded to the nearest tenth)
The formula for the area of the top and bottom faces of the cylinder is: A = πr².
In this case, the radius is 4 feet. So, the area of each face is:
A = 3.14 * (4)²
= 50.24 ft² (rounded to the nearest tenth)
To find the total surface area, we add the lateral surface area to twice the area of a face:
Total surface area = lateral surface area + 2 * area of one face
= 75.36 ft² + 2 * 50.24 ft²
= 75.36 ft² + 100.48 ft²
= 175.84 ft² (rounded to the nearest tenth)
Therefore, the surface area of the outside of the cylinder is 175.84 square feet.
Adrian is painting the outside of a cylinder that he plans to use as a coffee table. The cylinder has a radius of 4 feet and a height of 3 feet. Adrian wants to paint all around the outside of the cylinder, including the top and bottom faces. In order to understand how much paint is needed, he wants to know the surface are of the outside of the cylinder. What is the surface area of the cylinder, measured in square feet? Use 3.14 for pi and round your answer to the nearest tenth.(1 point)
____ft2
1 answer