Looking at the figure, the angles BCA and DCE are vertical angles, therefore they are congruent.
So, using the sum of internal angles in the triangle DEC, we have:
[tex]\begin{gathered} CDE+DEC+DCE=180 \\ 74+DEC+48=180 \\ \text{DEC}=180-74-48 \\ DEC=58\degree \end{gathered}[/tex]
Since triangles ABC and DEC are congruent, we have [tex]\begin{gathered} ABC=\text{DEC} \\ 2x=58 \\ x=29 \end{gathered}[/tex]
