计算下面图形的面积。（单位：dm）1}4h3B+G's;_
1}4h3B+G's;_
算式：提示3l+].x8?)u;v1}4h3B+G's;_
答：面积是3u'^8z,X-f0A6w-}dm²。1}4h3B+G's;_