Mathematics is full of fascinating discoveries, but few are as famous as the Pythagoras theorem. Every child studying mathematics eventually learns that this theorem connects the sides of a right-angled triangle. But have you ever wondered: Who really invented Pythagoras theorem?
Most people immediately think of Pythagoras, the ancient Greek mathematician, but history tells a more complex story. The roots of this theorem stretch far beyond Greece, reaching into Babylonian, Indian, and Chinese civilizations. In this blog, we’ll explore the origins, the role of Pythagoras, the global contributions, and why this theorem continues to shape learning for children today.
Also Read: What is Pythagoras Theorem?
The Pythagoras theorem states:
Hypotenuse² = Base² + Perpendicular²
(or, in standard form: c² = a² + b²)
It is one of the most fundamental results in geometry. While students learn it as a formula, its origins are deeply historical. The question “Who invented Pythagoras theorem?” doesn’t have a single answer—it involves centuries of discoveries.
When we hear the word Pythagoras, the first thing that comes to mind is the famous Pythagoras theorem. But who was this man, and why is he so important in the history of mathematics?
Pythagoras was a Greek mathematician and philosopher who lived around 570 BCE to 495 BCE. He was born on the island of Samos in Greece and later traveled widely to study different cultures and knowledge systems. Many historians believe he visited Egypt and Mesopotamia, where he learned geometry, astronomy, and religious practices before returning to Greece.
Pythagoras eventually settled in a city called Croton (in present-day southern Italy), where he founded a community known as the Pythagorean school. This was not just a school for mathematics but also a place where students lived and followed strict rules about diet, behavior, and learning. The members were known as Pythagoreans, and they treated mathematics almost like a religion, believing that numbers were the foundation of the universe.
One of the most famous contributions linked to Pythagoras is the Pythagoras theorem. It explains the special relationship between the sides of a right-angled triangle. However, it’s important to note that Pythagoras may not have been the very first to discover this relationship. Evidence shows that Babylonians and Indians knew about this principle much earlier. Still, Pythagoras is credited with providing the first logical proof and spreading it widely through his school.
Apart from the theorem, Pythagoras also worked on:
Numbers and ratios – He studied odd and even numbers and their properties.
Music and mathematics – He discovered that musical notes could be explained using simple ratios of string lengths, linking math with harmony.
Philosophy – Pythagoras taught that the soul is immortal and goes through rebirth, a belief that influenced later thinkers.
Pythagoras’s influence was so great that even though much of his life is mixed with legend, his name has become immortal in mathematics classrooms worldwide. Whenever a student solves a problem with the formula a² + b² = c², they are continuing the legacy of a man who lived more than 2,500 years ago.
It’s natural to think that because we call it the Pythagoras theorem, Pythagoras must have been the very first person in history to discover it. But here’s an interesting truth: mathematicians in other ancient civilizations knew about this relationship long before Pythagoras was even born.
So why is Pythagoras still so famous? Let’s explore:
Long before Greece, the Babylonians in Mesopotamia (present-day Iraq) were already using mathematical tablets to solve problems involving right-angled triangles. One of the most famous tablets is called Plimpton 322, which shows a list of Pythagorean triplets (like 3, 4, 5 and 5, 12, 13). These were used for construction and land measurement.
However, there is no written proof that the Babylonians understood or proved the theorem the way we do today. They used the numbers correctly, but it was more practical than theoretical.
In ancient India, scholars wrote texts called Sulba Sutras, which were instructions for building altars. One of these, written by a sage named Baudhayana, contains a clear statement that matches the Pythagoras theorem:
“The diagonal of a rectangle produces both areas which its length and breadth produce separately.”
That’s almost exactly the same as saying a² + b² = c²! This shows that Indian scholars knew the relationship several centuries before Pythagoras.
In ancient China, a classic math text called Zhou Bi Suan Jing described a version of the theorem, particularly with the famous 3-4-5 triangle. The Chinese used it for astronomy and surveying.
Even though other civilizations used the theorem, Pythagoras is believed to be the first person to give a logical, step-by-step proof. That’s why we credit the theorem to him — he turned practical knowledge into a theoretical foundation for geometry.
He also taught it systematically through his school, and because Greek mathematics was passed down through written works and scholars like Euclid, it became part of the Western mathematical tradition.
So, was Pythagoras the first? Probably not. But he was likely the first to prove it formally and make it famous. That’s why his name has remained attached to this beautiful mathematical idea.
One of the main reasons we remember Pythagoras is because he was not just satisfied with using the theorem — he wanted to prove it logically. His proof is one of the most famous in the history of mathematics. While there are now over 350 different proofs of the Pythagoras theorem (including geometric, algebraic, and even visual ones), the method attributed to Pythagoras is both elegant and simple.
The theorem says:
In a right-angled triangle, the square on the hypotenuse = sum of the squares on the other two sides.
Or, in math form:
c² = a² + b²
Where:
c = hypotenuse (the longest side)
a and b = the other two sides
Pythagoras wanted to show this using geometry rather than just numbers.
Draw a large square.
Imagine a big square with each side equal to (a + b).
Place four identical right-angled triangles inside.
Each triangle has sides a, b, and c. Arrange them so that they form a smaller square in the center.
Look at the empty space.
The central empty space forms a smaller square with side length c.
Calculate the area in two ways.
First, the area of the large square is (a + b)².
Second, the area can also be written as the sum of the areas of the four triangles plus the area of the small square in the center.
That means:
(a + b)² = 4 × (½ × a × b) + c²
Simplify the equation.
(a + b)² = 2ab + c²
a² + 2ab + b² = 2ab + c²
a² + b² = c²
And that is exactly the Pythagoras theorem!
It is visual, making it easier for children and beginners to understand.
It shows how geometry and algebra can work together.
It reflects the Greek tradition of logical reasoning, where nothing was accepted until proven.
Historians are not 100% sure if this exact method came from Pythagoras himself or from his school of mathematicians (the Pythagoreans). However, this proof is so closely linked to him that it has been passed down through history under his name.
For parents:
Knowing history helps children see maths as storytelling, not just formulas.
It improves curiosity and deeper understanding.
For students:
Learning the origins makes the theorem easier to remember.
Helps in answering higher-order thinking questions in exams.
Builds appreciation for how maths connects civilizations.
The relationship was known to Babylonians, Indians, and Chinese, but Pythagoras is credited with proving it systematically.
No. The theorem existed long before him in multiple civilizations.
Because he (or his school) provided the first mathematical proof, making it a formal theorem.
It was first applied in construction and land measurement in Babylon and India.
Yes, the Baudhayana Sulba Sutra records it clearly.
Over 400 proofs exist today, from geometry to algebra.
It makes math more interesting and gives context beyond exams.
