$$\left. \begin{array} { l } { A = ( a - 2 ) - ( b - \sqrt { 2 } ) } \\ { B = ( b - r ) - ( a - 2 r ) } \\ { C = ( a - 1 ) - ( b + 1 ) } \end{array} \right.$$
$r\in \mathrm{C}$
$A=a-b+\sqrt{2}-2$
$a\in \mathrm{C}$
$b\in \mathrm{C}$
$B=r+b-a$
$C=a-b-2$
$r\in \mathrm{R}$
$A=a-b+\sqrt{2}-2$
$a\in \mathrm{R}$
$b\in \mathrm{R}$
$B=r+b-a$
$C=a-b-2$
