圆周率 (yuán zhōu lǜ) — pi (the mathematical constant, approximately 3.14159)

Definition

noun
pi (the mathematical constant, approximately 3.14159)

Examples

  • 圆周率。
    yuán zhōu lǜ Shì yí gè wú xiàn bù xún huán xiǎo shù.
    Pi is an infinite non-repeating decimal.
  • 圆周率。
    Tā bèi chū le yuán zhōu lǜ xiǎo shù diǎn hòu yì bǎi wèi.
    He recited one hundred digits of pi after the decimal point.
  • 圆周率。
    Jì suàn yuán de miàn jī xū yào yòng dào yuán zhōu lǜ.
    Calculating the area of a circle requires using pi.

Origin

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.

圆周circumference
圆yuáncircle周zhōucircumference
偏正Modifier + head
率lǜratio

圆 circle and 周 circumference make 圆周, and 率 ratio gives 圆周率 as pi.

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.

This origin belongs to the traditional form 圓; 圆 is its simplified writing.

Meaning part形符xíngfú
囗囗wéi
Sound part声符shēngfú
員
員yuán圓yuán
Same sound today

This is about the traditional form 圓, not the simplified 圆. In 圓, 囗 surrounds 員, and the inner part of 員 is an old circle picture.

Open 圆 →

A drawing of the thing itself, worn down over three thousand years into a few strokes.

The oldest form of 周 drew a jade artifact with carved patterns. It was later borrowed for a place name, so an extra mark was added to distinguish it.

Open 周 →

A drawing of the thing itself, worn down over three thousand years into a few strokes.

率 was drawn as a bird-catching net, with a stick above and below. In the form described, the lower horizontal stroke is missing, so the whole shape represents a rope.

Open 率 →

Browse more HSK 7-9 words or search the full 43,000-word dictionary.