在坐标系中画出四边形ABCD然后做长方形EFGH,
由题意,得
S四ABCD=S长EFGH-S△ABD-S△ADE-S△BCF-S△CDG
=3×4-1×2×1/2-1×3×1/2-1×2×1/2-2×2×1/2
=12-1-1.5-1-2
=6.5
在坐标系中画出四边形ABCD然后做长方形EFGH,
由题意,得
S四ABCD=S长EFGH-S△ABD-S△ADE-S△BCF-S△CDG
=3×4-1×2×1/2-1×3×1/2-1×2×1/2-2×2×1/2
=12-1-1.5-1-2
=6.5