law of tangents

In single point incremental forming(SPIF),the final thickness of a deformed sheet can be predicted by the sine law,the formability in SPIF can be expressed as the maximum wall angle that a sheet would endure without fracturing.

在单点渐进成形中,成形零件的厚度满足正弦定律,成形极限用最大成形角表示。

The geometric proof of the law of tangents was the most complex formula in the plane trigonometry.

《崇祯历书》将西方三角学引入中国,正切定理是平面三角学中证明最复杂的一个公式,《大测》、《测量全义》分别将欧洲玉山若干、芬克的证明法介绍到中国。