The total surface area of the oatmeal carton can be calculated by finding the lateral surface area of the cylinder and adding the area of the top circle.
Lateral surface area = height x circumference of the base
Lateral surface area = 9 in x π x diameter
Lateral surface area = 9 in x π x 7 in
Lateral surface area = 63π in²
Area of the top circle = πr²
Area of the top circle = π(7/2)²
Area of the top circle = π(49/4)
Area of the top circle = 49π/4 in²
Total surface area = Lateral surface area + Area of the top circle
Total surface area = 63π in² + 49π/4 in²
Total surface area ≈ 235.5 in²
Therefore, approximately 235.5 square inches of cardboard are used to make the oatmeal carton.
A cylindrical carton of oatmeal has a diameter of 7 in and is 9 in tall. If all surfaces except the top are made of cardboard, how much cardboard is used to make the oatmeal carton? Round your answer to the nearest tenth. (1 point) Responses
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