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

    ReplyDelete

Share your solution or comment below! Your input is valuable and may be shared with the community.