Surface Area of Cones Practice
Math 8 Q2 (Pre-Algebra) / Cones, Cylinders, & Spheres
Use the image to answer the question.
A cone shows a radius of 6 and hypotenuse or side as 11.
what is the surface area of the cone? use 3.14 for pi and round to the nearest tenth, if necessary.
To find the surface area of a cone, we need to calculate the area of the curved lateral surface and the area of the base.
The formula for the lateral surface area of a cone is given by:
Lateral Surface Area = π*r*l
where r is the radius of the base and l is the slant height or the length of the side.
In this case, the radius of the base is 6 and the length of the side is 11. So, we have:
Lateral Surface Area = 3.14 * 6 * 11
Lateral Surface Area = 208.68 (rounded to the nearest hundredth)
The formula for the area of the base of a cone is given by:
Base Area = π*r^2
where r is the radius of the base.
In this case, the radius of the base is 6. So, we have:
Base Area = 3.14 * 6^2
Base Area = 3.14 * 36
Base Area = 113.04
To find the surface area of the cone, we add the lateral surface area and the base area:
Surface Area = Lateral Surface Area + Base Area
Surface Area = 208.68 + 113.04
Surface Area = 321.72 (rounded to the nearest hundredth)
Therefore, the surface area of the cone is approximately 321.72 square units.