Hello, the lack of corners refers to the lack of corners in the southwest and northwest of your house, which leads to an uneven house. A house with good geomantic omen shows that the floor plan is square and has no missing corners.
Gan represents the northwest, the owner of the family, Kun represents the southwest and the hostess of the family. If these two directions are really missing, there is a way to crack them.
Hope to adopt, thank you!