勾こう股こ弦げん

こ

う

こ

げ

ん

Meanings

noun

three sides of a right triangle

rare term

Rare mathematical term referring collectively to the shorter leg (勾), longer leg (股), and hypotenuse (弦) of a right triangle. Mainly encountered in classical Chinese mathematics or historical Japanese texts.

勾こう股こ弦げんの定てい理りは、中ちゅう国ごくの古こ典てん数すう学がくで詳くわしく扱あつかわれている。
The theorem of the three sides of a right triangle is treated in detail in classical Chinese mathematics.

See all 2 example sentences ›

Kanji

勾be bent, slope, capture
股thigh, crotch
弦bowstring, chord, hypotenuse
鈎hook, barb, gaff

Related words

直ちょっ角かく三さん角かく形けい
Standard modern term for 'right triangle'; 勾股弦 is an archaic collective term for its three sides.
三さん平へい方ほうの定てい理り
Common Japanese name for the Pythagorean theorem; 勾股弦 relates to the same geometric concept but refers to the sides themselves.

Word family

勾こう股こ弦げんの定てい理り
Pythagorean theorem

Written forms

勾こう股こ弦げん
Rare kanji spelling for the three sides of a right triangle; 勾 is the shorter leg, 股 the longer leg, and 弦 the hypotenuse.
鈎こう股こ弦げん
Variant spelling using 鈎 for the shorter leg; equally rare.

Etymology

From classical Chinese mathematical terminology; 勾 (shorter leg), 股 (longer leg), and 弦 (hypotenuse) together denote the three sides of a right triangle. The reading is on'yomi.