Saturday, February 9, 2013

Problem 855: Quadrilateral, Triangle, Angles, 30 degrees, Congruence, Auxiliary lines

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

Click the figure below to see the complete problem 855.

Online Geometry Problem 855: Quadrilateral, Triangle, Angles, 30 degrees, Congruence, Auxiliary lines

3 comments:

  1. The perpendicular from point B, to the AC meet AD at point E. Because AC, it's height and bisector of the triangle ABE, is isosceles. So, angle AEB= 77 degrees. The triangle BEC , is equilateral. So ,angle DBE =86-60=26 degrees ,therefore angle BDE=77 degrees .Then, BD=BE=BC .So ,from the triangle BDC , 86+2(30+X)=180 .So, x=17 degrees
    Plan: http://img832.imageshack.us/img832/3616/p855triangleangle30degr.gif

    ReplyDelete
  2. Generalizare:
    Fie ABE un triungi isoscel AB=AE cu m( x= 30-13=17

    ReplyDelete
  3. https://skydrive.live.com/redir?resid=9CEB7CF0BE40CF54!165&authkey=!ALVmbNF8RsZL6UQ

    ReplyDelete