解:
(1) 由化简得:$AC=2,$$AB=2\sqrt{5},$$BC=2\sqrt{2},$
$△ ABC$的周长为$2+2\sqrt{5}+2\sqrt{2};$
过点$B$作$BD⊥ AC$交$AC$的延长线于$D,$$BD=2,$
$△ ABC$的面积为$\frac{1}{2}× AC× BD=\frac{1}{2}×2×2=2。$
(2) 最长边为$AB=2\sqrt{5},$设该边上的高为$h,$
$\because S_{△ ABC}=\frac{1}{2}× AB× h=2,$
$\therefore \frac{1}{2}×2\sqrt{5}× h=2,$
解得$h=\frac{2}{\sqrt{5}}=\frac{2\sqrt{5}}{5}$