- 1直徑
The diameter of a circle is a straight line from one side to the other that goes through the centre. People also use the word for how long that line is: the diameter is ten . You meet it first in maths, then on , plates, coins, wheels, and trees — anything round enough that “how wide through the middle?” is a useful question. Though actually, a tree trunk is not a perfect circle, but people still say its diameter, meaning the width through the middle. The short line from the centre out to the edge is the radius; the diameter is twice as long. It is a classroom and measuring word, not a one, but anyone who has put a ruler across a round thing has used the idea.
From the word’s history
From Old French diametre, from Latin diametros, from Ancient Greek diámetros 'line measuring across'.
源自希臘文 diámetros「量過去的線」。
組成From Old French diametre (French diamètre), from Latin diametros, from Ancient Greek διάμετρος (diámetros), a “line measuring across”: διά (diá, “across”) + μέτρον (métron, “measure”).
同家族的字
- diametricthe adjective from the same word
- diametricallythe adverb: completely opposite, from the two ends of a diameter
- metresame Greek métron, “measure” (the measuring unit, not a parking meter)
原始詞典資料4 筆記錄
以下是外部詞典記錄的用法，摘錄並精簡格式，我們還沒有寫成教學內容。上面的說明才是我們自己寫的；有些用法可能上面已經講過了。
diameternoun/daɪˈæmɪtə(ɹ)/
- 1
geometrymathematicssciencesAny straight line between two points on the circumference of a circle that passes through the center of the circle; a chord that passes through the center of the circle.
- 2
geometrymathematicssciencesThe length of such a line.
- In cases without good face contact, the diameter of the toolholder at the front of the flange or the tool itself should not be any larger than the gage diameter of the toolholder shank from a bending stiffness viewpoint.
- Viable non-malformed singleton pregnancies were selected for cerebellar measurements; transcerebellar diameter, (TCD), left and right cerebellar diameters (LCD, RCD).
- 3
geometrymathematicssciencesThe maximum distance between any two points in a metric space.
- 4
graph-theorymathematicssciencesThe maximum eccentricity over all vertices in a graph.
摘錄自 英文維基詞典 English Wiktionary，已精簡格式；依 CC BY-SA 4.0 授權使用，改動後的內容同樣以此授權提供。