You might not think there would be any use
Knowing the square of the hypotenuse
(Which is the sum, Pythagoras confides,
Of the squares of the opposite two sides.)
This theorem which comes from geometry,
Combined with bits of trigonometry,
Is useful when we calculate how far
It is to something distant, like a star.
He traveled much, and probably had learned
This theorem, which he proved when he returned.
He did invent mathematical abstraction,
And useful concepts, like that of the fraction.
But numbers, even fractions, wouldn’t do
For representing the square root of two.
He formed a cult of number-based fanatics
That practically invented mathematics.
Was working out how strings of different lengths
When plucked made different pitches to the ear. He
Could have called this notion his string theory.