Carlyle circle
English
Etymology
The idea of using such a circle to solve a quadratic equation is attributed to Thomas Carlyle (1795–1881).
Noun
Carlyle circle (plural Carlyle circles)
- (mathematics) A certain circle in a coordinate plane associated with a quadratic equation, having the property that the solutions of the equation are the horizontal coordinates of the intersections of the circle with the horizontal axis.
- Carlyle circles have been used to develop ruler-and-compass constructions of regular polygons.