1, expansion diagram:
(1) The side development diagram of the cylinder is rectangular (or square) and the cross section is also rectangular (or square), and the upper and lower bottom surfaces are equal.
(2) The side of the cone is fan-shaped and the normal section is triangular. When the upper bottom surface of a cylinder shrinks to a point, it becomes a cone.
2. Bottom surface:
(1) The cylinder is also the bottom surface.
(2) Above the cone is a vertex.
3. Vertex:
(1) cones have vertices;
(2) A cylinder has no vertex.
Extended data:
A, cone composition:
1, height of the cone: the shortest distance from the top of the cone to the center of the bottom of the cone is called the height of the cone.
2. Cone generatrix: the fan-shaped radius formed by the expansion of the side surface of the cone, and the distance from any point on the circumference of the bottom surface to the vertex.
3. Boundary area of the cone: expand the side generatrix of the cone to make it fan-shaped. The arc length of the sector is equal to the circumference of the cone bottom surface, and the radius of the sector is equal to the length of the cone generatrix. The boundary area of the cone is the circumference of the bottom of the cone, and the arc length is × generatrix /2. It is the surface before expansion.
4. A cone has a bottom, an edge, a vertex, a height and countless generatrixes. The base diagram is circular and the edge diagram is fan-shaped.
Second, the nature:
1. The two circular surfaces of a cylinder are called the bottom surface, and the surrounding surfaces are called the side surfaces. A cylinder consists of two bottom surfaces and one side surface.
2. The two bottom surfaces of a cylinder are the same round surface. The distance between the two bottom surfaces is the height of the cylinder.
3. The edge of the cylinder is a curved surface, and the developed figure of the cylinder edge is a rectangle, a square or a parallelogram (diagonal cutting).
4. The lateral area of the cylinder = the height of the perimeter of the bottom.