The following text was written to the standard output stream when the ShapesThing.java program was executed from IntelliJ. Note: Spaces have been added between the < and > signs in the output objects below so as to not mistakingly create HTML tags.
square = < Square: side=400.0 > area of square = 160000.0 perimeter of square = 1600.0 diagonal of square = 565.685424949238 disk = < Circle: radius=200.0 > area of disk = 125663.70614359173 perimeter of disk = 1256.6370614359173 diamond = < Square: side=282.842712474619 > area of diamond = 80000.0