<image>The ancient Chinese mathematical classic  "$$Nine Chapters on the Mathematical Art$$" recorded that in $$344$$ B.C., Shang Yang supervised the making of a standard volume measure--the Shang Yang Bronze Square Dou, the three views of which are shown in the figure ($$unit: cun$$). If $$π$$ is taken as $$3$$, its volume is $$12.6($$ cubic cun$$)$$, then the value of $$x$$ in the figure is ______ cun.