I took a clear plastic tube and attached two circle protractors that could be rotated up and down the tube.

我找来一只透明的塑料试管，然后将两支可以旋转并上下移动的量角器接到试管上。

Lay out plate, sheet steel or other heavy metal and mark bending and cutting lines on work piece using protractors, compasses and drawing instruments or templates.

铺设莱板，钢板或其他重金属，用量角器，圆规和绘图工具或模板在工件上标记弯曲和切割线。

The double-sided protractor comprises two identical protractors and is structurally characterized in that a rotating shaft is arranged in the center ofthe two overlapped protractors.

本实用新型包括两个相同的量角 器，其结构要点是在上下两个叠加量角器的中心上设置有转轴。