Geometry Problems, Online Education

Problem 721: Triangle, Orthocenter, Circumcircle, Altitude, Collinear. HS, College

In the figure below, H is the orthocenter of triangle ABC and AH, BH, CH extended meet the circumcircle O at A', B', C', respectively. P is a point on the circumcircle O and PA', PB', PC' meet BC, AC, AB at A", B", C", respectively. Prove that B", C" ,H ,A" are collinear.
 

Triangle, CIrcumcircle, Orthocenter, ALtitude, Collinear points
 

 

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Online education degree: online geometry classes

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Open Geometry Problems
Index

Squares, Circles, Collinear

Geometry Problem 722.
Squares, Circumscribed Circles, Collinear points.

Excenter, Intersecting circles

Geometry Problem 720.
Excenter, Intersecting Circles, Angle, Measurement.

Incenter, Intersecting circles

Geometry Problem 719.
Incenter, Intersecting Circles, Angle, Measurement.

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