The curve also permits the solution of the problems of duplicating a cube and **trisecting** an angle.

It became known as the "Delian problem" or the "problem of the duplication of the cube," and ranks in historical importance with the problems of "**trisecting** an angle" and "squaring the circle."

Although Hippocrates could not determine the proportionals, his statement of the problem in this form was a great advance, for it was perceived that the problem of **trisecting** an angle was reducible to a similar form which, in the language of algebraic geometry, is to solve geometrically a cubic equation.

TRISECTRI X, a curve which is a variety of the limacon of Pascal, and named from its property of **trisecting** an angle.

His investigation of the properties of amicable numbers and of the problem of **trisecting** an angle, are of importance.