Let the circles and used in the construction of the Brocard Points which are tangent to at and , respectively, meet again at . The points then define the D-triangle. The Vertices of the D-triangle lie on the respective Apollonius Circles.

**References**

Johnson, R. A. *Modern Geometry: An Elementary Treatise on the Geometry of the Triangle and the Circle.* Boston, MA:
Houghton Mifflin, pp. 284-285, 296 and 307, 1929.

© 1996-9

1999-05-24