Modeling of trapezoidal pattern raft foundation in staad foundation advance

Staad foundation advance (SFA) has an option to assign plates of various thickness, but it should also have an option to model such plates in TRAPEZOIDAL PATTERN as shown in below images,which is frequently used to model raft foundation, also placement and bending of reinforcement at site for trapezoidal pattern plates is very convenient compared to earlier pattern (different thickness of plates in uniform pattern)..