The following text was written to the standard output stream when the ShapesThing.java program was executed from IntelliJ.
square = Square: side=400.0> area of square = 160000.0 perimeter of a square = 1600.0 diagonal of a square = 565.685424949238 disk = Circle: radius=200.0> disk area = 125663.70614359173 perimeter of a disk= 1256.6370614359173 diamond = Square: side=282.842712474619> diamond area = 80000.0