1, polyhedron: Generally speaking, we call the geometry surrounded by several planar polygons polyhedron. Each polygon contained in a polyhedron is called the face of the polyhedron; The common edge of two adjacent faces is called the edge of polyhedron; The common point between edges is called the vertex of a polyhedron.

2. Revolving body: We call the closed geometry formed by a plane figure rotating around a fixed straight line in its plane a revolving body. This fixed line is called the axis of the rotating body.

3. Prism: Generally speaking, two faces are parallel to each other, the other face is a quadrilateral, and the common sides of every two adjacent quadrilaterals are parallel to each other. A polyhedron surrounded by these faces is called a prism. In a prism, two parallel faces are called the bottom face of the prism, which is called the bottom face for short; The other faces are called the sides of the prism; The common side of the adjacent side is called the side of the prism; The common vertex of the edge and the bottom is called the vertex of the prism.

4. Cylinder: A rotating body surrounded by straight lines with one side of a rectangle as the rotation axis and the other three sides rotating is called a cylinder. The axis of rotation is called the axis of the cylinder; The circular surface formed by the rotation of the edge perpendicular to the axis is called the bottom surface of the cylinder; The surface formed by the rotation of a side parallel to the axis is called the side of the cylinder; No matter where it rotates, the surface that is not perpendicular to the axis is called the generatrix surface of the cylinder.

5. Pyramid: Generally, one face is a polygon and the other faces are triangles with a common vertex. The polyhedron surrounded by these faces is called the pyramid, and this polygon face is called the bottom or bottom of the pyramid; Each triangular face with a common vertex is called the edge of the pyramid; The vertex of the male cone on each side is called the pyramid vertex; The common side of adjacent sides is called the side of a pyramid.

6. Cone: The rotation body surrounded by the straight line where the right side of the right triangle is located as the rotation axis and the other two sides are rotated is called a cone. A cone also has an axis, a bottom surface, a side surface and a generatrix.

7. Prism: Use a plane parallel to the bottom of the pyramid to cut the part between the bottom of the pyramid and the section. This polyhedron is called a prism.

8. frustum: cut the cone with a plane parallel to the bottom of the cone. The part between the bottom and the section is called a truncated body. The frustum also has a shaft, a bottom surface, a side surface and a bushing.

9. Ball: The rotating body formed by taking the straight line with the diameter of the semicircle as the rotation axis and the semicircle surface rotating once is called a sphere, which is called a ball for short. The center of the semicircle is called the center of the ball, the radius of the semicircle is called the radius of the ball, and the diameter of the semicircle is called the diameter of the ball.