direct edge

• 定向棱

direct edge的用法和样例：

例句

1. The curved edge at the junction of two intersecting vaults.
   穹棱肋在两交叉的穹顶相接处的呈曲线状的边缘。
2. He fell, striking his head on the edge of the table.
   他摔倒了，头碰在桌棱上。