Li Shengxue's pyramid is triangular. Triangle is a closed figure composed of three line segments on the same plane but not on the same straight line, which has applications in mathematics and architecture. Li Shengxue's pyramid cap is square at the bottom and triangular at the side, so Li Shengxue's pyramid cap is triangular. Pyramids are distributed in Egypt and America. Because these huge tombs are shaped like gold characters of Chinese characters, we call them pyramids. The pyramids are the tombs of ancient Egyptian kings. These rulers were called pharaohs in history. Ancient Egyptians' devout belief in God made them form a deep-rooted concept of the afterlife very early. They even think that life is only a short stay, and after death it is a permanent enjoyment.