假设图中A点为学校大门，学校升旗台在学校大门口正北方向30米处，知新楼在大门北偏东30°的40米处，试画出示意图．（按1：2000的比例尺画）4分．
直接写得数.+= += 1﹣= ﹣= ﹣= ﹣=++1= ++= += += 1﹣﹣= +﹣=
口算.+= ﹣= +﹣= 3+=+= 1﹣﹣= ++= 4﹣=
计算：．
= ．
+
= 
+
= 1﹣
= 
﹣
= 
﹣
﹣
=
+
+1= 
+
+
= 
+
= 
+
= 1﹣
﹣
= 
+
﹣
=
+
﹣
= 
+
﹣
= 3+
=
+
= 1﹣
﹣
= 
+
+
= 4﹣
=
．
= ．
= ．
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