Math Geometry Problems, Online Education

 Problem 136. Orthic Triangle, Altitudes, Orthocenter, Incenter, Perpendicular, Concyclic Points.

In the figure below, given a triangle ABC and its orthic triangle DEF (AD, BE, and CF are the altitudes of ABC). H is the orthocenter of triangle ABC, L, M, N are the tangency points of the incircle of triangle DEF and DG and DK are perpendicular to BE and CF respectively. Prove that D, G, N, H, M, and K are concyclic points (lie on a circle). View or post a solution.
 

Geometry Problem: Orthic triangle, concyclic points
 

 

 

 Home | Geometry | Wolfram Demonstrations Project | Altitude | Search | Problems | Art | 131-140 | Orthic Triangle | Email | View or post a solution | By Antonio Gutierrez