直径

• 拼音: zhí jìng
• 汉字拆解: 直 = straight; 径 = 彳 + 圣 (path — a direct route)

含义

Diameter; the straight line passing through the centre of a circle connecting two points on its circumference.

A mathematical and technical term. Used in geometry, engineering, and everyday measurement. Contrasted with 半径 (radius) and 周长 (circumference). Also used figuratively for something's span or reach.

例句

1. 这个水管的直径是五十毫米，足够满足供水需求。
2. 月球的直径约为地球直径的四分之一。
3. 工程师测量了轴承的直径，确认规格符合设计要求。

用法指南

语境: mathematics, engineering, measurement

语气: technical

正确说法

• 请计算出这个圆的直径和面积。(Please calculate the diameter and area of this circle.)
• 这条隧道直径达到十五米，是亚洲最大的盾构隧道之一。(This tunnel has a diameter of fifteen metres and is one of the largest shield tunnels in Asia.)

错误说法

• 这个正方形的直径 — squares have 对角线 (diagonal), not 直径; diameter is only for circles and spheres

起源与历史

直 (straight) + 径 (path/line) — the straight path through the centre

文化背景

世代: All ages

社会背景: Universal