It's very simple to cut a round cake into eight pieces just by cutting it three times. The cake can be regarded as a cylinder:

1. Lay the cake flat, and cut a knife across the cylindrical body of the cake, as shown by the black dotted line in the figure, that is, the cake is cut into two layers:

2. Then stand the knife up and cut a knife down in the horizontal direction on the top of the cake, as shown by the black dotted line in the figure, so that it has been cut into four pieces:

3. As shown by the black dotted line in the figure, it has been cut into eight pieces:

Extended information

Cake originated in the west, and then it was slowly introduced to China.

Cake is a symbol of ancient religious myths and miraculous superstitions. The early economic and trade routes imported exotic spices from the Far East to the north, nuts, toilet water, citrus fruits, dates and figs from the Middle East, and sugar cane from eastern and southern countries.

In the dark ages of Europe, these rare materials were only possessed by monks and nobles, and their pastry creations were honey gingerbread and flat hard biscuits. Slowly, with the frequent trade, the eating habits of western countries have changed completely.