China
In BC 1 1 century, Shang Gao, a mathematician in Zhou Dynasty, put forward "hook 3, strand 4, string 5". A dialogue between Shang Gao and Duke Zhou was recorded in The Book of Balance Calculation in Zhou Dynasty. Shang Gao said: "... so fold the moment, tick three, fix four, and cross the corner five." Meaning: When two right-angled sides of a right-angled triangle are 3 (hook) and 4 (chord) respectively, the radius angle (chord) is 5. In the future, people will simply say that this fact is "three strands, four chords and five". According to this allusion, Pythagorean theorem is called quotient height theorem.
In the 3rd century A.D., Zhao ·suan in the Three Kingdoms period made a detailed annotation on Pythagorean Theorem in The Book of Changes, which was recorded in Nine Chapters of Arithmetic. Zhao Shuang created Pythagorean Square Diagram, which was obtained by combining shape and number, and gave a detailed proof of Pythagorean Theorem. Later, Liu Hui also proved the Pythagorean theorem in Liu Hui's notes.
Hua Hua, a mathematician in China in the late Qing Dynasty, put forward more than twenty proofs of Pythagorean theorem.
foreign country
The ancient Babylonians knew and applied Pythagorean theorem as early as around 3000 BC, and they also knew many Pythagorean sequences. There is an ancient Babylonian clay tablet numbered "Printon 322" in the library of Columbia University in the United States, on which a large number of checkers are recorded. The ancient Egyptians also used Pythagorean theorem when building magnificent pyramids and measuring the land after the Nile flooded.
In the 6th century BC, the Greek mathematician Pythagoras proved the Pythagorean theorem, so westerners used to call it Pythagorean theorem.
In the 4th century BC, the Greek mathematician Euclid gave a proof in the Elements of Geometry (Volume I, Proposition 47).
On April 1876 and 1 day, Garfield published his proof of Pythagorean theorem in the New England Journal of Education.
The Pythagorean proposition was published in 1940, and 367 different proofs were collected.
-Baidu Encyclopedia