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 2004-11-09 20:03:18