切线 (qiē xiàn) — (mathematics) tangent (line)

定義

例文

• 从圆外一点可以画两条切线。
  Cóng yuán wài yì diǎn kě yǐ huà liǎng tiáo qiē xiàn.
  From a point outside the circle, two tangents can be drawn.
• 切线与半径互相垂直。
  qiē xiàn Yǔ bàn jìng hù xiāng chuí zhí.
  The tangent is perpendicular to the radius.
• 这道题要求求出切线的长度。
  Zhè dào tí yāo qiú qiú chū qiē xiàn de cháng dù.
  This problem asks you to find the length of the tangent.