A Dictionary of Greek and Roman biography and mythology

(Δεινόστρατος), a geometer. He is stated by Proclus to have been the brother of Menaechmus, and a contemporary and follower of Plato. (Comm. in Eucl. c. iv.) The two brothers, according to Proclus, made the whole of geometry more perfect (τελεωτέραν) than before. Pappus (lib. iv. prop. 25) has handed down the curve which is called the quadratrix of Deinostratus for squaring the circle, which Nicomedes and

others afterwards used. This curve is made by the intersection of a revolving radius of a circle with a line moving perpendicular to the first position of that radius, both moving uniformly, and so that the extremity of the moving perpendicular descends from the circumference to the centre while the revolving radius describes a right angle.

[A. DE M.]