(1)三角形ABC的面积=3×3-
×1×3-1 2
×1×2-1 2
×2×3=9-5.5=3.5;1 2
(2)根据勾股定理,得
AB=
=
1+9
,AC=
10
=
1+4
,BC=
5
=
4+9
.
13
则三角形ABC的周长=
+
10
+
5
;
13
(3)点C到AB边的距离=
=7
10
7 10
.
10