> Hi all, > > I need help with this problem: > > http://img180.imageshack.us/img180/8286/20080218181526nq7.gif > > The angle to find is ECD. > > The matter is solving it without trigonometric functions. > With trigonometry or by drawing it you can see that the angle to find > is 20° (sessagesimal) but I can't find it using a simple solution > (properties of triangles, the parallel postulate and so on). > > Can you solve it?
Interesting problem, couldn't solve it either. I get 4 unknowns but only 3 linearly independent equations.