20-30-130 Triangle Problem

Given  triangle ABC with an angle of 20 degrees at A bisected by AF and  an angle of 30 degrees at B cut by segment BE  such that angle ABE is 10 degrees and angle CBE is 20 degrees.    What is the measure of angle DCE?

GSP file

Hints? Warning! These may not be helpful. The hints are in GSP files.

Hint 1

Hint 2

Hint 3