Online Geometry Problems

Geometry Problem 1120: Isosceles Right Triangle, 120 Degree, Angle, Equilateral, Metric Relations. Level: High School, SAT Prep, Honors Geometry, College, Math Education

< PREVIOUS PROBLEM  |  NEXT PROBLEM >

The figure below shows an isosceles right triangle ABC. D is a point so that angle ADC = 120 degree. E is on CD extended so that angle BEC = 120 degree. BE extended meets AD at F. If AD = d, CE = e, and BF = f, prove that (1) triangle DEF is equilateral; (2) Problem 1120, formula to prove.
 

Infographic Geometry Problem 1120: Isosceles Right Triangle, 120 Degree, Angle, Equilateral, Metric Relations
 

 

Selected Topics

Home | SearchGeometry | Problems | All Problems | Open Problems | Visual Index | 10 Problems | 1111-1120 | Triangle | Right triangle | Isosceles Triangle | Equilateral triangle | Angles 30, 60, 120 degree | Email | Solution / comment.
Last updated: Jun 11, 2015 by Antonio Gutierrez.