Brief article on this early Sophist, from the Internet Encyclopedia of Philosophy.

Wikipedia entry on this ancient polymath, including some material from the 1911 Britannica.

Constructed from excerpts from various of Plato's dialogues which mention this Sophist.

Concise scholarly biography of this discoverer of the quadratrix, from the MacTutor History of Mathematics.

Some brief notes on Hippias' attempt to square the circle using this curve, "a pictorial representation of the irrationality of pi."