The following text was written to the standard output stream when the ShapesThing program was executed from IntelliJ.
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 circumference of disk = 1256.6370614359173 diamond = Square: side=282.842712474619 area of diamond = 80000.0 Process finished with exit code 0