bisecting compasses

例句：

1. 1. The ancient map was divided into sections for easy navigation.
   古老的地图被分成了易于导航的部分。
2. 2. He used a bisecting compass to find the center of the room.
   他用一个分割指南针找到了房间的中心。
3. 3. The carpenter used a bisecting compass to mark the corners of the table.
   木匠用一个分割指南针来标记桌子的角落。