an additional piece of info in the question, which i forgot to type, is:
g is onto - that is, for every y in R, there is an x such that g(x) = y.
anyway, i tried reparameterizing according to arclength. let s1, s2, s3 = arclength of f, g, and h.
functions are f = f(t), and g = g(b)...