切点

zài cǐ jī chǔ shang qiú chū shǒu yuán hú kōng jiān qiē diǎn xiàn hé jiǎ bǎn biān xiàn de xiū zhèng duàn

在此基础上，求出首圆弧空间切点线和甲板边线的修正段。

The locus of space tangent point and the arc segment of deck at side are obtained based on the above conditions.