![](https://img.51dongshi.com/20250107/wz/18421904152.jpg)
作一個(gè)平面直角坐標(biāo)系,并將點(diǎn)A{-2,8},點(diǎn)B{-11,6},點(diǎn)C{-14,0},點(diǎn)D{0,0}標(biāo)如圖中.(1)作BE、AF⊥x軸,垂足為E、F.S四邊形ABCD=S△CBE+S△AFD+梯形ABEF=ah/2+ah/2+(a+b)h/2=3×6/2+2×8/2+(6+8)×9/2=9+8+63=80(2)把四邊形ABCD各個(gè)頂點(diǎn)縱坐標(biāo)保持不變,橫坐標(biāo)增加2,就是將四邊形ABCD向右平移2格.圖形平移后,位置改變,形狀與大小不變.所以四邊形ABCD的大小仍是80.不知對(duì)不對(duì).