1. The bottom surface of the cone is a (circular) surface and the side surface is a (fan-shaped) surface. The distance from the apex of the cone to the center of the cone bottom is the height of the cone, and the cone is (? ) surface, there is (a) high.

2. You can get a (cone) body by rotating the right-angled side of a right-angled triangle as the axis, and this axis is the height of the cone. The other angle is a cone (side length? )。

3. Name the parts of the cone.