$a=-\sqrt{c^{2}-b^{2}}$
$a=\sqrt{c^{2}-b^{2}}$

$b=-\sqrt{c^{2}-a^{2}}$
$b=\sqrt{c^{2}-a^{2}}$

$a=\sqrt{c^{2}-b^{2}}$
$a=-\sqrt{c^{2}-b^{2}}\text{, }|c|\geq |b|$

$b=\sqrt{c^{2}-a^{2}}$
$b=-\sqrt{c^{2}-a^{2}}\text{, }|c|\geq |a|$