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

Definition

noun

(mathematics) tangent (line)

Measure word · 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。
qiē xiàn Yǔ bàn jìng hù xiāng chuí zhí.
The tangent is perpendicular to the radius.
切线。
Zhè dào tí yāo qiú qiú chū qiē xiàn de cháng dù.
This problem asks you to find the length of the tangent.

Compound word

构词法gòucífǎ

偏正piānzhèngModifier + head

The first part narrows down the second: it says what kind of thing the head is.

切 names the tangent action and 线 names a line, together meaning tangent.

Characters in this word

Most characters — around four in five — are built this way: one part hints at the meaning, the other at the pronunciation.

七刀切

Meaning part形符xíngfú

刀刀dāoknife

Sound part声符shēngfú

七

七qī切qiè

The sound has drifted apartThe sound part was a clue two thousand years ago — it often still helps, but not always.

In 切, the 刀 (knife) part is joined to 七, which gives the sound.

Most characters — around four in five — are built this way: one part hints at the meaning, the other at the pronunciation.

This origin belongs to the traditional form 線; 线 is its simplified writing.

糹泉線

Meaning part形符xíngfú

糹Written in full as糸mì

Sound part声符shēngfú

泉

The sound has drifted apartThe sound part was a clue two thousand years ago — it often still helps, but not always.

The traditional form 線 uses 糹 (silk/thread) to show the meaning and 泉 to suggest the sound; the simplified 线 is a later shorthand.