Hippocrates of Chios

Definition: Hippocrates of Chios was a Greek mathematician of the fifth century B.C. who wrote the first known elements of geometry. Although it is no longer extant, Euclid probably used it. Proclus (c. A.D. 410–485) and Simplicius of Cilicia (fl. c. A.D. 530) make reference to Hippocrates' geometry.