Friday, July 17, 2015

Geometry Problem 1139: Triangle, Circumcircle, Angle Bisector, Parallel Lines, 90 Degrees, Concurrent Lines

Geometry Problem. Post your solution in the comments box below.
Level: Mathematics Education, High School, Honors Geometry, College.

Click the diagram below to enlarge it.

Online Math: Geometry Problem 1139: Triangle, Circumcircle, Angle Bisector, Parallel Lines, 90 Degrees, Concurrent Lines.

1 comment:

  1. Line FG meets Circle O at point K,
    Angle BKG = Angle C/2
    Also in Triangle GHB Angle BHG = Angle C/2
    So Quad BGKH is cyclic
    Angle HGB = Angle A/2 = Angle HKB
    Since Angle DKB = Angle A/2
    HDK must be collinear
    Similarly JEK must be collinear
    it proves FG, HD and JE are concurrent at K.
    QED

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