Thursday, February 13, 2014

Geometry Problem 980. Equilateral Triangle, Vertices, Three Parallel, Equal Circles, Construction

Geometry Problem
Level: Mathematics Education, High School, Honors Geometry, College.

Click the figure below to see the complete problem 980.

Online Geometry Problem 980. Equilateral Triangle, Vertices, Three Parallel, Equal Circles, Construction

1 comment:

  1. Because AC//DF and BD//CE, 60=<BOC=<BDF, 60=<AOQ=180-<ACF=<DFC, then <DFC=<BDF so OCDF is cyclic isosceles trapezoid. But 60=180-<QOD=<ECF so <DFC=<ECF which makes FEDC isosceles trapezoid as well. That means DEOCF is cyclic and OEF equilateral from subtended angles.

    ReplyDelete