The missing corner of a building refers to the missing corner on one side of the building, or within two-thirds of the missing corner. The house is concave or inclined, irregular square or fuzzy inclined polygon, and its center of gravity is shifted, light and biased, or inclined from left to right, or large in front and small in back.
More than 2/3 is a serious lack of angle. If it is less than 2/3, it is not the main direction that is missing. For example, the southeast corner of the house is missing, which is the position of the eldest daughter. It doesn't matter much if there is no daughter at home.