Why are there eight diagrams of Yin and Yang in the school building?

After the building is completed, due to the influence of some natural environment, sometimes the location of the building will violate some feng shui principles, such as whether there is a road evil spirit, a light evil spirit, or others. This bagua mirror will be used to keep bad things back. It's like when you leave the house, you will cover it with a cover. If there is a road under your window, the light will be refracted into your window when a car passes by, so you will put a mirror to refract the light again.