http://img395.imageshack.us/img395/9...heangelfk4.png
all the angles are given how do u find the angle that has a question mark beside it?
http://img395.imageshack.us/img395/9...heangelfk4.png
all the angles are given how do u find the angle that has a question mark beside it?
Klicken sie Heir.
Sorry, Krizalid I used trigonometry to solve it. I am not as good in Classical Geometry as you are.
Here's a picture
Take a point $\displaystyle F$ such that $\displaystyle \overline{CF}=\overline{CE}~\wedge~\measuredangle~ BCF=20^\circ$
You need to prove two facts:
Finally, you'll see that quadrilateral $\displaystyle BCDF$ is cyclic, and the problem is done.
- $\displaystyle \overline{AD}=\overline{BC}$
- $\displaystyle D,\,E,\,F$ are collinear.
Good luck!