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.

The numbers add up but I can't quite prove why.

Angle EDC is 60°.

After drawing a line from D parallel to line BE and labeling the point where the new line crosses line AE I can't prove that the new point (G) is the midpoint between A and E.  Like I said, my numbers add up, but I can't quite prove why.

Posted by Erik O. on 2004-11-02 18:13:09