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