How much do you know about the paper format

　　Paper is used everywhere in life, but do you really understand what size paper A1 and B2 are?

　　The specification of paper means that after the paper is made, it is trimmed and cut to a certain size. In the past, the size of the paper was expressed by the number of "opens" (such as 8 karat or 16 karat, etc.). Now our country adopts international standards, which stipulate that the paper is represented by A0, A1, A2, B1, B2... The format specifications. The standard stipulates that the ratio between the width (indicated by X) and the length (indicated by Y) of the paper is X:Y=1:n.

　　According to the basic area of ??the paper format, the format specifications are divided into A series, B series and C series. The format size of A0 format is 841mm×1189mm, and the format area is 1 square meter; the format size of B0 is 1000mm×1414mm. The area is 1.5 square meters; the format size of C0 is 917mm×1279mm, and the format area is 1.25 square meters; the format specification of copy paper only adopts A series and B series. If the A0 paper is split into two equal parts along the length, it becomes the A1 size. If the A1 paper is split along the length, it becomes the A2 size, so it is split to the A8 size; the B8 paper is also split to B8 in this way. specification. The format sizes of A0～A8 and B0～B8 are listed in the table below. Among them, A3, A4, A5, A6 and B4, B5, B6 and B7 are commonly used specifications for copy paper.