What is the surface area, in square inches, of a cone with a radius of 10 inches and a slant height of 15 inches? Use 3.14 for pi.(1 point)
Responses
785 square inches
785 square inches
1,177.5 square inches
1,177.5 square inches
471 square inches
471 square inches
2,198 square inches
The correct answer is:
785 square inches
Use the image to answer the question.
A cone shows a base diameter of 25 centimeters, perpendicular height from the base to the top vertex at 90 degrees, and 22 centimeters as the hypotenuse or the side of the cone.
What is the surface area of the cone? Use 3.14 for pi.
(1 point)
Responses
1,354.125 square centimeters
1,354.125 square centimeters
3,689.5 square centimeters
3,689.5 square centimeters
2,383.26 square centimeters
2,383.26 square centimeters
863.5 square centimeters
The correct answer is:
863.5 square centimeters
A spyglass in the shape of a cone has a slant height of 18 centimeters and a radius of 6 centimeters. What is the surface area of the spyglass? Use 3.14 for pi.(1 point)
Responses
452.16 square centimeters
452.16 square centimeters
1,356.48 square centimeters
1,356.48 square centimeters
197.82 square centimeters
197.82 square centimeters
339.12 square centimeters
The correct answer is:
339.12 square centimeters
A designer is creating a modern art sculpture of an hourglass out of steel, to be on display at the town library. The hourglass is made by two cones meeting at the top point. The designer wants to know how many square feet of steel is needed for the outside of the sculpture, if the slant height of each cone is 5 feet and the diameter is 8 feet. Use 3.14 for pi.(1 point)
Responses
226.08 square feet
226.08 square feet
113.04 square feet
113.04 square feet
326.56 square feet
326.56 square feet
653.12 square feet
To calculate the surface area of the hourglass sculpture, we need to find the lateral surface area of each cone and then add them together.
The formula for the lateral surface area of a cone is given by: A = πrs, where r is the radius and s is the slant height.
First, we calculate the radius by dividing the diameter by 2:
radius = 8 feet / 2 = 4 feet
Next, we calculate the lateral surface area of each cone:
LSA = π * 4 feet * 5 feet = 20π square feet
Since we have two cones, we multiply the lateral surface area of one cone by 2:
total LSA = 20π square feet * 2 = 40π square feet
Finally, we approximate π to be 3.14 and calculate the surface area:
surface area = 40 * 3.14 square feet = 125.6 square feet
The correct answer is:
113.04 square feet
A cone-shaped megaphone has a radius of 15 centimeters and a slant height of 20 centimeters. A megaphone has an open bottom. What is the lateral surface area of the megaphone, in square centimeters? Use 3.14 for pi.(1 point)
Responses
1,648.5 square centimeters
1,648.5 square centimeters
109.9 square centimeters
109.9 square centimeters
942 square centimeters
942 square centimeters
1,884 square centimeters
The lateral surface area of a cone is given by the formula A = πrs, where r is the radius and s is the slant height.
Given that the radius is 15 centimeters and the slant height is 20 centimeters, we can calculate the lateral surface area as follows:
LSA = π * 15 centimeters * 20 centimeters = 300π square centimeters
Approximating π to be 3.14, we have:
LSA = 300 * 3.14 square centimeters ≈ 942 square centimeters
The correct answer is:
942 square centimeters