For a Nonzero Real Number and a Triangle , swing Line Segment about the vertex towards vertex through an Angle . Call the line along the rotated segment . Construct a second line by rotating Line Segment about vertex through an Angle . Now denote the point of intersection of and by . Similarly, construct and . The Triangle having these points as vertices is called the Hofstadter -triangle. Kimberling (1994) showed that the Hofstadter triangle is perspective to , and calls Perspective Center the Hofstadter Point.

**References**

Kimberling, C. ``Hofstadter Points.'' *Nieuw Arch. Wiskunde* **12**, 109-114, 1994.

Kimberling, C. ``Hofstadter Points.'' http://cedar.evansville.edu/~ck6/tcenters/recent/hofstad.html.

© 1996-9

1999-05-25