The circular bus bar is the line AB in the figure. Side of the table: The curved part is called the side of the table. Height of the table: The common vertical line between the two bottom surfaces is called the height of the table. Bus bar of the round table: the waist of the rotating right Angle trapezoid that is not perpendicular to the bottom is called the bus bar of the round table. The bottom side of the round table: the top and bottom sides of the round table are two round faces, which are called the bottom side of the round table. Round table: Round table is a rectangular trapezoid perpendicular to the bottom of the waist as the axis, the right Angle trapezoid rotation 360° formed geometry. Extended data: The line or surface that controls the movement of the bus is called a wire or guide surface, and the position of the bus on the surface is called a prime line, as shown in Figure 1. Curve AB is the wire, straight line SB is the bus, and each position of SB moving is a prime line. The curved surface formed when the bus bar is a straight line is called a straight grain surface; The curved surface formed when the bus is a curve is called a curved surface. The surface formed by regular busbar movement is called regular surface. The points, lines and surfaces that control the movement of busbars are called fixed points, conductors and guide surfaces. Reference source: Encyclopedia - Round table Reference source: Encyclopedia - Bus bar