This is fill in the blanks

This is a bit hard to fill in the blanks for, so I'm just gonna explain what is happening in the proof...

First, the proof used If parallel, then alternate interior angles are congruent.  Then it uses vertical angles are congruent.  Then it uses C as a midpoint to get two segments congruent.  Then you can get that the triangles are congruent by Angle, Side, Angle.  The with CPCTC(Corresponding Parts of Congruent Triangles Congruent) to get BC congruent to DC.

Hope it helps <3

Step-by-step explanation:

1) AB // DE                  Given

2) AC = CE                 Definition of midpoint

3) ∠ABC = ∠EDC      Alternate interior angles are congruent

4)∠ACB = ∠ECD       Vertically opposite angles are congruent

5) ΔACB ≅ ΔECD      SAA Congruent of triangles

6) BC ≅ DC                CPCT --> corresponding Part of Congruent Triangle

answer: x=60