It seems evident from infinitely many primitive pythagorean triples (a,b,c)$(a,b,c)$ that there are infinitely many rational points (a/c, b/c)$\left(\frac{a}{c}, \frac{b}{c}\right)$ on the unit circle.
But how would one go about, and show that they are dense, in the sense that for two rational points x$x$ and y$y$ of angles α$α$ and β$β$ on the unit circle, if α<β$α<β$ there is
a third rational point z$z$ of angle γ$γ$ on the unit circle, such that α<γ$α<γ$ and γ<β$γ<β$.
Is it to expect that this conjecture holds and that it isn't an unsolved number theory problem?