The dumplings can't be put into the water to disperse immediately, so the stability also becomes very important. As we know, triangle is a very stable shape, and it is often used for reinforcement in life. The four outer surfaces of the tetrahedron are all triangles, so that the dumplings are not easy to deform and lead to fall apart and leak.
The simplicity of packaging is also a major feature of tetrahedral dumplings. Even if you haven't wrapped zongzi, people who have eaten zongzi can understand that the packaging of zongzi depends only on a long strip of zongzi leaves without any modification of cutting. Long leaves can be bent to form a tetrahedron directly after bending, and the outside of the binding rope can also be tightly one will be fixed. Nowadays, there are also some new shapes of rice dumplings on the market, such as long strips of rice dumplings, which are usually made of multiple rice dumpling leaves stacked on top of each other, and are also secured by multiple ropes on the outside, which is very troublesome.
Finally, tetrahedrons also maximize the efficient use of space. Whether you are wrapping tamales at home or commercially, the number of tamales is relatively large. To cook your own packaged dumplings as fast as possible in a stove with limited space, rational use of space for efficient stacking is key. Obviously, the tetrahedron meets this requirement, and its corners can maximize the space occupied and increase space utilization.