The Clifford point of a complete quadrilateral or of four lines in a general position is a special point in the (Euclidean) plane, that is defined through four circles associated with those four lines. It is named after William Kingdon Clifford (1845-1879), who proved theorems related to it (Clifford's circle theorems).
References edit
- Liang-shin Hahn: Complex Numbers and Geometry. Cambridge University Press, 1994, ISBN 9780883855102, S. 67-71