trisecting

trisecting

1. trisecting forceps

三分钳

2. forceps for upper stumps, trisecting

上颌残根三分钳

3. forceps for lower stumps, trisecting

下颌残根三分钳

4. Vajna-Thising trisecting forceps

瓦-蒂二氏三分钳

5. Vajna's trisecting forceps

瓦纳(氏)三分钳

6. Trisecting an arbitrary angle with a compass and straightedge was one of the famous ancient Greeks unsolved construction problems.

用直尺和圆规三等分一个任意的角是古希腊著名的构造问题之一。