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。