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Geometry Problem 731: Cyclic quadrilateral, Triangle, Orthocenter, Altitude, Perpendicular, Parallelogram. Level: High School, Honors Geometry, College, Mathematics Education

The diagram shows a cyclic quadrilateral ABCD. If E is the orthocenter of triangle ABD and F the orthocenter of triangle ACD, prove that BCFE is a parallelogram.
 

Cyclic quadrilateral, Diagonals, Orthocenter, Parallelogram

 

 

Home | SearchGeometry | Problems | All Problems | Open Problems | Visual Index | 731-740 | Cyclic Quadrilateral | Triangles | Orthocenter | Altitude | Perpendicular lines | Parallelogram | Email | Solution / comment | By Antonio Gutierrez