[tex] 2*\sqrt{8 - \sqrt{8}} = 2*\sqrt{8 - 2\sqrt{2}} \text{ There isn't much more you can do except change this to a decimal}[/tex]
[tex] 2*\sqrt{8 - 2.8284} = 2*\sqrt{5.1716} = 2*2.2741=4.5482 [/tex]