$ (2)解：由圖已知點(diǎn)A(-2,0)，點(diǎn)C(0,2)$
$設(shè)AC解析式為y=kx+2將點(diǎn)A代入解得$
$k=1$
$AC解析式為y=x+2$
$D到AC的距離為\frac {|-1-\sqrt{3}+2|}{\sqrt{1+1}}=\frac {\sqrt{3}-1}{\sqrt{2}}$
$AC=\sqrt{OC^2+OA^2}=2\sqrt{2}$
$S_{△ACD}=\frac12×2\sqrt{2}×\frac {\sqrt{3}-1}{\sqrt{2}}$
$=\sqrt{3}-1$
