
 Compare surface areas of the cylinder and the cone.
 Regarding the cylinder and the cone created during the previous hour, set a learning situation to think which container can be created with smaller paper.
 Confirm that the areas of the developments coincide with the surface areas of the figures.
 Summarize how to obtain the area of the sector.
 Confirm the meanings of “surface area,” “base area,” and “lateral area.”
 Through the comparison of the volumes of the cylinder and the cone, summarize inductively that the surface areas of the threedimensional figures coincide with the areas of the developments.
* When the areas of the developments are obtained, the areas of the known figures need to be obtained and totaled. Thus, it is considered that this point can be summarized as the matter common to all threedimensional figures.
