How to expand the whole piece symmetrically?

Symmetrically unfolding an entire piece of ET can be achieved through the following steps:

1. First, fully unfold the ET so that it takes on the shape of a straight line.

2. Next, according to the principle of symmetry, unfold the two ends of the ET outwards so that it presents a symmetrical shape.

3. During the unfolding process, attention should be paid to maintaining the symmetry of ET and ensuring that the expansion amplitude and shape of the left and right sides are the same.

In this way, the symmetric expansion of ET can be achieved.

As for why ET should be expanded symmetrically, there are the following reasons and extensions:

1. Aesthetics: Symmetric expansion can make ET present a more beautiful and balanced shape. Symmetry is one of the important factors in the perception of beauty by the human eye, so symmetrically unfolded ET is more easily accepted and appreciated by people.

2. Structural stability: Symmetric expansion can make all parts of ET evenly distributed, increasing the stability and solidity of its structure. If ET becomes asymmetric during deployment, it may cause some parts to be too weak and prone to breakage or deformation.

3. Production process: Symmetric expansion helps simplify the design and operation of the production process. Symmetry can provide a template or guide for ease of use, making the process smoother and more efficient.

In general, symmetrically unfolding ET can improve its aesthetics, structural stability, and simplify the production process, making it more in line with people's aesthetic and practical needs.