Go Geometry Problems

Online Geometry Problem 738: Intersecting Circles, External Common Tangent, Common Chord, Secant, Circumcircle, Cyclic Quadrilateral, Concyclic Points. Level: High School, Honors Geometry, College, Mathematics Education

In the diagram below, the circles O and O' intersect at A and B. CD is the common tangent. CA meets circle O' at F, DA meets circle O at G. GC and FD meet at H. BA meets GH at M. The circumcircles of triangles FGH and CHD meet at N. Prove that the points B, C, M, N are concyclic.
 

 Intersecting Circles, Common Tangent
 

Home | SearchGeometry | Problems | All Problems | Open Problems | Visual Index | 731-740 | Circles | Intersecting Circles | Intersection of a Line with a Circle | Circle Tangent Line | Circumcircle | Cyclic Quadrilateral | Common Chord | Email | Solution / comment | By Antonio Gutierrez