Yes, the upper and lower bottoms of a trapezoid are generally indistinguishable. The trapezoid is short at the upper bottom and long at the lower bottom. That's it. Generally speaking, the upper length and the lower length are stored in * * *, the upper length is the upper bottom, and the lower length is the lower bottom.

If the upper bottom is long and the lower bottom is short, it is defined as up and down, the upper bottom is the upper bottom and the lower bottom is the lower bottom. ....

Remember to give me the best ~~! =.=-& lt； -& lt； -& lt； @