Euler in Babylon

Perfect right-angled triangles

November 22, 2008

Consider the right angled triangle with sides a=7, b=24 and c=25. The area of this triangle is 84, which is divisible by the perfect numbers 6 and 28. Moreover it is a primitive right angled triangle as gcd(a,b)=1 and gcd(b,c)=1. Also c is a perfect square.

We will call a right angled triangle perfect if -it is a primitive right angled triangle -its hypotenuse is a perfect square

We will call a right angled triangle super-perfect if -it is a perfect right angled triangle and -its area is a multiple of the perfect numbers 6 and 28.

How many perfect right-angled triangles with c≤1016 exist that are not super-perfect?


gamwe6

Written by gamwe6 who lives and works in San Francisco building useful things. You should follow him on Twitter