Diamond shape is a special and rare shape, which usually appears at the top, usually acts as a reverse breakthrough shape, and is rarely used as a continuous finishing shape. The diamond is a combination of trumpet and symmetrical triangle, that is to say, the first half is an enlarged triangle and the second half is a symmetrical triangle. In this form, it shows that the two edges gradually separate, and then gradually recombine to form a chart shape that is particularly similar to a diamond, so it is called a diamond shape.