円周

えんしゅう

circumference

JLPT N2

Character Breakdown

Understanding 円周 (えんしゅう)

The word 円周 specifically refers to the circumference of a circle, which is the distance around the circle's edge. It is a common term in geometry and mathematics, often used in formulas and calculations involving circles.

Common Collocations and Patterns

  • 円周を計算する: to calculate the circumference
  • 円周率 (えんしゅうりつ): the ratio of circumference to diameter, known as pi (π)
  • 円周の長さ: the length of the circumference

These collocations are frequently used in academic and everyday contexts when discussing measurements related to circles.

Usage Notes

円周 is a technical term and is mostly used in formal or educational contexts. When talking about the circumference in casual conversation, people might simply say 円のまわり (around the circle), but 円周 is the precise term.

A common learner mistake is confusing 円周 (circumference) with 円 (circle) itself. Remember, 円周 refers only to the boundary length, not the area or the circle as a whole.

Example Sentences

このえんのえんしゅうをけいさんしてください。

Please calculate the circumference of this circle.

えんしゅうりつはやくさんてんいちよんです。

The value of pi (circumference ratio) is approximately 3.14.

えんしゅうのながさはちょっけいにパイをかけたものです。

The length of the circumference is the diameter multiplied by pi.