Sara needs to cover the top and sides of the cylinder below. (1 point)
h=12 r=8 v=?
About how many square inches for paper will Sara need?
A.352 in2
B.402 in2
C.804 in2
D. 1,005 in2
top = pi r^2
sides = 2 pi r h
pi (64 + 16*12)
pi (64 + 192)
256 pi = about 804
To find the number of square inches of paper Sara will need to cover the top and sides of the cylinder, we first need to calculate the surface area of the top and the lateral surface area of the cylinder.
1. To calculate the surface area of the top of the cylinder, we use the formula for the area of a circle: A = πr^2, where r is the radius of the circle. In this case, the radius is 8, so the area of the top is A = π(8^2) = 64π.
2. To calculate the lateral surface area of the cylinder, we use the formula for the lateral area of a cylinder: A = 2πrh, where r is the radius of the base and h is the height of the cylinder. In this case, the radius is 8 and the height is 12, so the lateral area is A = 2π(8)(12) = 192π.
3. To find the total surface area, we add the surface area of the top and the lateral surface area: Total surface area = surface area of top + lateral surface area = 64π + 192π = 256π.
4. Finally, we need to approximate the value of π to find the approximate number of square inches of paper Sara will need. The value of π is approximately 3.14.
Approximate total surface area = 256π ≈ 256(3.14) ≈ 804 square inches.
Therefore, the answer is C. 804 in2.