Question

what is the Pythagoras

Answer 1

Pythagoras theorem means the square of the hypotenuse is equal to the sum of the squares of other two sides in a triangle.

Answer 2

here is your answer
Pythagoras is a theorem that states
${hypotenues}^{2} = {base}^{2} + {perpendicular}^{2}$
it only fits in right angled triangle.

in which longest side = hypotenues
base line is called base and other one is perpendicular...

hope it helps you