noun
Archaic term for the Pythagorean theorem, now almost entirely replaced by ピタゴラスの定理. Found in older mathematical texts.
See also: ピタゴラスの定理
江戸時代の和算書には「勾股弦の定理」という言葉が使われている。
The term 勾股弦の定理 is used in Edo-period Japanese mathematics books.
The modern standard term for the Pythagorean theorem; 勾股弦の定理 is its archaic predecessor.
From Chinese mathematical terminology, where 勾 (base), 股 (height), and 弦 (hypotenuse) refer to the sides of a right triangle. The term was adopted into Japanese mathematics before Western influence.