Online Geometry theorems, problems, solutions, and related topics.
Geometry ProblemLevel: Mathematics Education, High School, Honors Geometry, College.Click the figure below to see the complete problem 770.
http://img542.imageshack.us/img542/8173/problem770.pngDraw lines per attached sketchNote that ADE, CEF and ABF are isosceles triangles.And BO⊥CE , ∠ECO=∠CEO= 90- αAD=BC=DE∆ OCB congruence to ∆ODE … ( Case SAS)So OB=OD and triangle BOD is isoscelesX= (180-72)/2=54
To Peter Tran:Please explain why BO ⊥ CEWhere it is used?Pravin
http://img62.imageshack.us/img62/9149/problem7701.pngPravinThank you for your comment. The correct statement should be CO ⊥EF instead of BO⊥ CE . The solution and the result is valid with this correction. See attached sketch above for details