$a^2+b^2=c^2$

$b^2+c^2=a^2$

$a^2-b^2=c^2$

$c^2+a^2=b^2$

$c^2-a^2=b^2$

$b^2-c^2=a^2$

$a^2-b^2=c^2$

$b^2-a^2=c^2$

$c^2-a^2-b^2=0$

$a^2+b^2+c^2=0$

$a^2-b^2-c^2=0$

$b^2-a^2+c^2=0$

$\sin x=\cos y$

$\tan x=\tan y$

$\sin x=\tan y$

$\tan x=\cos y$