Question

$${ a }^{ 2 } = { b }^{ 2 } + { b }^{ 2 }$$

Solve for a

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

Solve for b

$b=\frac{\sqrt{2}a}{2}$
$b=-\frac{\sqrt{2}a}{2}$