In order to know the height of the pyramids, the king of ancient Egypt invited a scholar to solve this problem. At a certain moment, the scholar confirmed that its shadow length was equal to his height in the sun, and immediately asked the assistant to measure the shadow DB of the 32m-long pyramid and the CD at the bottom of the 230m-long pyramid, so that he could accurately calculate the height of the pyramid. How did he work it out?
Answer: Because the pyramid is a regular pyramid, the projection of the vertex on the bottom is the center o of the bottom, and the distance from o to each side is half of the side length, that is, 230/2= 1 15m, while the shadow is outside the bottom, so the height plus the shadow length is 1 15.
This is because the shadow length of a scholar is equal to his height in the sun, so the height of the pyramid is equal to its shadow length! This applies to similarity.