Euclid's algorithm can be used not only for integers but for any
two numbers.
You could use the same method for this problem as given in the
article
Approximations, Euclid's Algorithm and Continued Fractions
for finding rational approximations to
.
In this method you write the process down in terms of continued
fractions.
Alternatively, see the article by Benjamin Wardhaugh in the Plus
magazine entitled Euclid's Algorithm and Music which shows a
method for solving this problem. The examples given there use
different numbers. If you use this method it might be easier if
you write down your working using the factorizations of the
numbers involved, rather than writing them out in full.