[HM] Pythagorean triples and unit circle

Franz Lemmermeyer (franz@athene.math.uni-sb.de)
Mon, 16 Nov 1998 12:30:20 +0100 (CET)

Today, creating Pythagorean triples is most easily done
by parametrizing the unit circle: you pick any point
on it, say P = (-1,0), and compute the intersection
of the circle with a line with rational slope through P.
Does anybody know where this geometric method first occurs?

thanks,

franz