Tuesday, March 11, 2014

Geometry Problem 992: Triangle, Interior Point, Angles, 20, 30 , 40, 50 Degree

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

Click the figure below to view the complete problem 992

Online Geometry Problem 992: Triangle, Interior Point, Angles, 20, 30 , 40, 50 Degree.

4 comments:

  1. http://s25.postimg.org/7jzp7p7zz/Pro_992.png

    Draw altitude CE of isosceles triangle ABC
    We haves angles as shown on the sketch
    D is the center of incircle of triangle AFC => angle DCF=10
    So x= 180-60-10= 110

    ReplyDelete
  2. If E is the circumcenter of tr. ABD, then tr. ADE is equilateral (1) and, easily, tr. ACE and BEC are isosceles; with (1) CD is bisector of <ACE, making <BCD=30,hence <BDC=110.

    Best regards

    ReplyDelete