be vertices of regular pentagon inscribed in a circle whose radius is 
and center is at 
.
Y by Mango247
Dear Mathlinkers,
1. ABC an acutangle triangle
2. H the orthocenter
3.DEF the orthic triangle orthique
4. (O) the circumcircle of ABC
5. P the point of intersection of EF and AH
6. Y, Z the second point of intersection of (O) wrt BP, CP
7. X the point of intersection of YE and ZF.
Prove : X is on (O).
Sincerely
Jean-Louis
1. ABC an acutangle triangle
2. H the orthocenter
3.DEF the orthic triangle orthique
4. (O) the circumcircle of ABC
5. P the point of intersection of EF and AH
6. Y, Z the second point of intersection of (O) wrt BP, CP
7. X the point of intersection of YE and ZF.
Prove : X is on (O).
Sincerely
Jean-Louis
