 
Summary: PLIMPTON 322
ROGER C. ALPERIN
Plimpton 322 records information on 15 rightangled triangles. The
exact method used for the table is not known.
It is known how to parameterize right triangle sides in terms of in
teger parameters a, b: the sides are x = a2
 b2
, y = 2ab and the hy
potenuse is z = a2
+b2
satisfying the Pythagorean Theorem x2
+y2
= z2
.
In Babylonian times one used base 60. Consider the numbers w = a
b
having prime factors in {2, 3, 5}. For our description let w = 2i
3j
5k
; the
