Meaning and Usage
"直径" (zhíjìng) specifically refers to the length of a straight line passing through the center of a circle or sphere, connecting two points on its boundary. It is a fundamental geometric term used in mathematics, engineering, and everyday measurements.
Common Contexts
You will often hear "直径" when discussing shapes, sizes of round objects like pipes, wheels, or plates, and in technical settings requiring precise measurements.
Collocations and Patterns
- 直径是... (The diameter is...) — used to state the size of a circular object.
- 测量直径 (measure the diameter) — common in practical measurement contexts.
- 直径大小 (diameter size) — emphasizes the dimension aspect.
Usage Notes
"直径" is a noun and is always used to describe a physical measurement. It contrasts with "半径" (radius), which is half the diameter. Avoid confusing these two terms. "直径" is always a full length across the circle through its center.
Register and Tone
The term is neutral and formal, suitable for scientific, educational, and technical conversations. It is not used metaphorically or in casual slang.