if you can solve it in first chance, you are a genius......
here it is
Given a triangle ABC, side AB = side AC. Draw a line from C to
side AB. Call that line CD. Now draw a line from B to side AC. Call
that line BE. Let angle EBC = 60 degrees, angle BCD = 70 degrees, angle ABE = 20 degrees, and angle DCE = 10 degrees. Now draw
line DE. Find angle EDC. Do not do this trigonometrically; do it
geometrically to get an exact answer.