円えん周しゅう

え

ん

しゅ

う

Common wordJLPTN2Freq.FrequencyTop 50,000

Meanings

noun, noun which may take the genitive case particle 'no'

Refers to the distance around a circle. Often used in mathematical contexts.

〈物もの〉の円えん周しゅうを求もとめるto calculate the circumference of something
この円えんの円えん周しゅうを求もとめなさい。
Find the circumference of this circle.
円えん周しゅうの長ながさthe length of the circumference
円えん周しゅうの長ながさは直ちょっ径けいにπを掛かけて求もとめられる。
The length of the circumference is found by multiplying the diameter by π.

直ちょっ径けいN2
円周 is the distance around a circle, while 直径 is the straight line through its center, so learners often confuse which measurement is being asked for.
半はん径けいN2
円周 refers to the full perimeter of a circle, whereas 半径 is only half the diameter, a distinction that beginners frequently mix up.
円えん弧こ
円周 refers to the entire circumference of a circle, whereas 円弧 refers to only a portion (arc) of that circumference.
円えん柱ちゅう
円柱 names the solid cylinder shape itself, while 円周 refers only to the circumference of a circle, despite the shared 円 kanji.

Compound of 円 (circle) and 周 (circumference, perimeter). The reading is on'yomi.