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.
The missing corner of the house is centered on the center of the house, and the farthest point connecting the house is drawn as a circle (including the inner balcony, but excluding the outer balcony and bay window). If the length of the missing corner is equal to or greater than the whole radius 1/2, it can be regarded as missing corner, and more than 2/3 is regarded as serious missing corner.