Triangle ABC is isosceles with AB=AC. Point D is on side AB such that angle BCD is 70 degrees.
Point E is on side AC such that angle EBC is 60 degrees.
Angle ABE equals 20 degrees, and angle DCE equals 10 degrees.
Find angle EDC. Justify your answer.
(In reply to
re: Generalization by Jils)
I generalized because this problem is similar to Langley's problem ( do a Google on "Langley's Problem" to see a synthetic proof ). I solved for angle EDC as a function of angles CBE and BCD. These angles are given for this problem and Langley's.

Posted by Bractals
on 20041109 20:03:18 