X = Plan length of the building for X direction
Xp = Reentrant plan length of the building for X direction
Y = Plan length of the building for Y direction
Yp = Reentrant plan length of the building for Y direction
Reentrant corner irregularity is defined to exist where dimensions of projections in both of the two perpendicular directions in plan exceed the total plan dimensions of that story of the building in the respective directions by more than 15%
In buildings with reentrant corner-type irregularities, story slabs are modeled with two-dimensional plates (membrane) or finite shell elements to show they can safely transfer earthquake forces between vertical bearing system elements in their own planes.