9 in.
8 in.
7 in.
Claire says that in order to calculate the surface area of the cone, she needs to use 8 in. Miles says that in order to calculate the surface area of the cone, he needs to use 9 in. Who is correct and why?
1 answer
Claire is correct. In order to calculate the surface area of a cone, you need to use the slant height of the cone, which is the distance from the base to the tip of the cone along the curved surface. The slant height is different from the height of the cone. It is calculated using the height and radius of the cone by using the Pythagorean theorem. Since Claire mentions the 8 in measurement, it is likely that she is referring to the slant height, which is needed for surface area calculations. On the other hand, Miles mentions the 9 in measurement, which could be the height of the cone. However, the height alone is not enough to calculate the surface area of the cone. Therefore, Claire's statement is correct.