i need hep with Pythagorean Triples

[Yoda]

Is there a formula for working them out?
or can anyone help with:

a^2 + b^2 = c^2 + d^2

[Virgil]

In article <7rmf92$ber$1...@news8.svr.pol.co.uk>, "Yoda"
<ni...@yoda80.freeserve.co.uk> wrote:

A Pythagorean triple is a set of natural numbers a,b,and c such that
a^2 + b^2 = c^2.

If a and b of a Pythagorean triple are coprime (have no common factors
greater than 1, then it is called a *primitive* Pythagorean triple.

Every primitive triple is of the form
a = u^2 - v^2, b = 2*u*v, c = u^2 + v^2 or
a = 2*u*v, b + u^2 - v^2 , c = u^2 + v^2,
where u and v are coprime natural numbers and u > v.

Every Pythagorean triple is of the form
a*k, b*k, c*k, where a,b,c is a primitive triple and K is a natural number.

Note that when u = 2, v = 1, and k = 1, you get {a,b,c} = {3,4,5},
which is the best known Pythagorean triple.

--
Virgil
vm...@frii.com