Expand the side of the cone into a fan shape.
A cone has a base, a vertex and only one height.
Surface area of cone = 1/2× bus × bottom perimeter+bottom area.
Cone volume formula: v = 1/3sh
I have also seen that the volume of a cylinder is three times that of a cone with equal base and equal height. I thought, is that right? I happen to have a pair of cylindrical and conical teaching AIDS at home. Both teaching AIDS are hollow with openings. Why don't I try?
I first filled the cone with water and poured it into the cylinder, but it was not filled; Another "cup" was poured, but it was still not full; Pour it again and finally fill it with cylindrical teaching AIDS. It seems that this is true! I filled the cylindrical teaching aid with water and poured it into the cone cup by cup. Sure enough, I also poured three cups.
Mathematics is really wonderful! I sighed heartily.